雅礼中学2008年5月月考
英语试题
第一部分 听力（共三节，满分30分）
第一节（共5小题，满分7.5分）
听下面5段对话，每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项。听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。
1. When
will the two speakers leave if they get cheaper tickets?’
A. On Tuesday.
B. On Thursday.
C. On Friday.
2. What
is the probably relationship between the two speakers?
A. Husband and wife. B. Passenger and driver. C.
Salesgirl and customer.
3. What
does the man imply?
A. He got help from the
woman.
B. He needed more time to study.
C. He worked hard for his
composition.
4. What
will the woman do in the morning?
A. See Lisa off.
B. Go to the zoo. C. Deal with an e-mail.
5. Where
does this conversation most probably take place?
A . In a bus. B. In an office.
C.
In a phone box.
第二节 （共12小题，满分18分）
听下面4段对话。每段对话后有几个小题，从题中所给的A、B、C三个选项中，选出最佳选项，听每段对话前，你将有时间阅读各个小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。每段对话读两遍。
听下面一段对话，回答第6和第7两个小题。
6. Where
will the man have his dinner?
A. At Golden Pond Restaurant.
B. At Black Forest
Restaurant.
C. At Moon River Restaurant.
7. What
do we know about the man?
A. He wants to eat beef.
B. He likes to
have dinner late.
C. prefers to wear a jacket and
tie.
听下面一段对话，回答第8至第10三个小题。
8. How
does the man feel about the delay of his flight?
A. Calm.
B.
Glad.
C.
Angry.
9. Which
is the right boarding gate for the man?
A. Gate 5.
B.
Gate 20.
C.
Gate 38.
10. When
will the plane probably take off?
A. At 3:30 p.m.
B.
At 3:40 p.m.
C. At 3:50 p.m.
听下面一段对话，回答第11至第13三个小题。
11. What
are the two speakers mainly talking about?
A. Eco-tours.
B. Popular
sports.
C. Famous countries.
12. Which
activity in the USA in introduced in the dialogue?
A. Mountain-climbing.
B. River-rafting.
C. Bird-watching.
13. How
many countries are mentioned in the dialogue?
A. Three.
B.
Four.
C.
Five.
听下面一段对话，回答第14至第17四个小题。
14. Why
does the man ask the woman for help?
A. He has to read a report.
B. He has to write a
report.
C. He has to wait for a call.
15. What
does the man ask the woman to do?
A. Buy some food.
B. Make tomato soup. C.
Bring back the café.
16. Which
of the following is suggested by the woman?
A. A pie.
B.
A salad.
C. A
sandwich.
17. What
does the woman think of the man?
A. Lazy.
B.
Greedy.
C.
Curious.
第三节（共3小题，满分4.5分）
听下面一段材料，将第18至第20三个小题的信息补充完整，每个小题不超过三个单词。 听材料前，你将有时间阅读各个小题，每个小题5秒钟； 听完后，各小题将给出15秒钟的作答时间。本材料读两遍。
第二部分 英语知识运用
第一节 单项填空 (共15小题, 满分15分)
从A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
21. On
_________ recent trip, Christine paid a visit to _________ relative she didn’t
know very well, one of her distant aunts.
A. a; a B. a; the
C.
不填; a
D. the; the
22. Many Chinese think less of money when _________ comes to
educating their children.
A. one B. he
C.
that
D. it
23.____the
freedom that young people have, dating has changed greatly in recent years.
A. In case of B. In
spite of C. In addition to
. D. As a result of
24. The police
officers stood at either end of the highway, _________ Ray, the drunken driver,
no chance to escape.
A. to give B. given C.
giving D.
gave
25.When I
got up early in the morning and was about to get dressed, I only saw one shoe
beside the bed and couldn’t find my _______ shoe.
A. another
B.
other
C. either D. others
25．I have kept that photo
________ I can see it every day, as it always reminds me of my unforgettable
experience in the country.
A. which B.
where C.
whether D.
when
26. He
was considering buying a new car but his parents______ it clear that they won’t
support him unless he can afford it himself.
A. were making B.
have made C. made D. will make
27. Only those
students ____ thinks the best can be accepted into the world famous university,
according to the
director of its admissions office.
A. who
B.
he
C.
that
D. what
28. The
escaped prisoner dared not leave the hiding place ______ he was recognized.
A. in case
B.
so that
C. the
moment D. even if
29. The
house rent here is really expensive. Tom has got about half the space he had at
home but he’s paying _______ here.
A. as twice much
B.
as much twice
C. much as twice
D.
twice as much
30. He was puzzled by
this phenomenon. He began to try every approach ________ the way of working it
out.
A. known finding B. knowing to find
C. known to find D. knowing finding
31. It is generally believed that
a successful Olympic Games _____ relies on well-performed IT services.
A．largely B．narrowly C．badly D．simply
32. I am
sorry that I cannot meet you at the airport. I _________ Changsha by the time
you come back from abroad.
A. am leaving B. will leave C.
will have left D. have left
33.Sir,
______ you meet the applicant right now or _____ he wait outside the office for
a while?
A. Shall; should B. Would; will C.
Can; will D.
Will; shall
34．The book is________
boring; I haven’t, as a matter of fact, read a more exciting and fascinating
one.
A. nothing but B.
anything but C.
more than D.
not a little
35. How
time flies!. It will be only a couple of days _________ the Olympic torch arrives
in our city as part of its journey to Beijing on August 8.,
A. before
B. after
C. until D. when
第二节 完形填空 (共20小题, 满分30分)
阅读下面短文，掌握其大意，然后从第36至第55小题所给的A、B、C、D四个选项中，选出最佳选项。
Old
Man Donovan was a mean man who hated children. He threw _ 36 _ at them and even shot at them with a gun. At least, that
was what we had _ 37 _.
His
small farm bordered our neighborhood _ 38 _ my younger
sister, Leigh Ann, and I lived when we were growing up. His farm was long and
narrow. It held two_ 39 _. One was his
beautiful fruit. There were many varieties of fruit: pears, apples and lots
more I _ 40_ can’t think of.. The fruit
naturally _ 41_the children to his farm
and made them into _ 42_, but my sister
and I didn’t dare to take his fruit because of what we had heard about Old Man
Donovan.
One
summer, we were playing in a nearby field until it was time for us to head back
home. My sister and I were feeling very _ 43_ that day. We decided to take the short cut that went
through the Donovan farm. We were almost through the farm _ 44_ we heard, “Hey, girls!” _ 45_ a gruff, low voice. We stopped _ 46_ in our tracks! There we were, face to face with Old Man
Donovan. Our knees were _ 47_. We had
visions of rocks pounding our bodies and _ 48_ going through our hearts.
“Come
here,”” he said, _ 49_ to one of his apple
trees. _ 50_ shaking, we went over to
him. He _ 51_ several ripe juicy red apples. “Take
these home”, he_ 52_. We took the apple
with 53_ hearts and ran all the way home. But of course, Leigh and
I ate the apples.
As
time went on, we often went through Old Man Donovan’s farm and he _ 54_ giving us fruit. One day, we stopped by and talked to him
for hours. We realized that we had found _ 55_ treasure: the sweet kind heart behind his gruff voice.
36.
A. fruit
B. wood
C.
branches D.
rocks
37.
A. heard
B.
seen
C.
experienced
D. expected
38.
A. that B. where C. which
D.
what
39.
A. attractions B. products C.
treasures
D.
secrets
40.
A. even
B. just
C.
hardly
D. ever
41.
A. signed B. showed C. guided
D.
drew
42.
A. customers B. visitors C.
thieves
D.
sufferers
43.
A. daring B. disappointed C.
afraid
D.
nervous
44.
A. and
B. when
C.
but
D.
while
45.
A. in
B. with
C.
behind
D.
by
46.
A. straight
B.
dead
C.
still D.
fast
47.
A. dropping
B. moving C. shaking D. fighting
48.
A. words
B. bullets
C.
guns
D. regrets
49.
A. reaching up B.
climbing up C. looking up D.
putting up
50.
A. Without B.
After C. Upon D. Still
51.
A. handed out
B.
gave out
C.
held out
D. picked out
52.
A. begged
B.
suggested C.
ordered
D. shouted
53.
A. excited
B.
surprised
C.
broken
D. angry
54. A.
stopped B.
considered C. admitted D. kept
55.
A. the other
B.
the fist
C. the
only D. the last
第三部分 阅读理解（共两节, 满分40分）
第一节 选择题（共17小题, 满分34分）
阅读下列短文, 从每题所给的A、B、C、D四个选中,
选出最佳选项。
A
As the first report of the accident came in, Burton was sitting in his office on the top
floor of the building. Immediately ,realizing the seriousness of the whole
incident, he moved to a ground floor room with a small waiting-room to look
into the matter himself, leaving his second ?in ?com-man to take over all other
cases.
He interviewed the first witness （证人）almost at once, making sure that everything was done that could be done
to put him at his ease. However, the witness was obviously nervous and Burton
took great pains to go over what he said thoroughly, hoosing
and checking each word carefully and taking the man’s statement down himself.The witness had called the police and he’d waited
until the ambulances began to arrive then when the first police car arrived on
the scene he’d been asked to report to the station which was what he had done.
Burton
explained that regrettably it would be necessary for him to go to court because
of the serious nature of the disaster. More he could not say at present. He’d
be thankful if the man could keep in touch with the police.
When he had gone, Burton put his head in
his hands and considered before asking for the next witness. The man couldn’t
be regarded as a hundred percent witness because he had been behind a wall
when the explosion occurred. But in spite of his nerves, Burton had the impression that he was
dependable, not afraid of relating himself to it and a fairly exact observer.
Well there would be other
descriptions and no doubt all these would be put into place and the whole
picture would become clear. He raised his head and pressed the bell on his desk.
“Next witness please,” he said.
56．Why
did Burton move
to the ground floor when he heard of the incident ?
A．Because
the ground floor room had a small waiting ?room.
B．Because
it would be easier for him to interview the witnesses.
C．Because
he was not pleased to work on the top floor.
D．Because
it would be easier for him to talk with the people.
57．How
did the witness feel during the interview ?
A．Obviously
somewhat frightened. B．Excited
at seeing the incident.
C．Anxious
to give a report to the police. D．Calm
and unhurried.
58．The
underlined part “ a hundred percent witness ”most probably means .
A．a
patient and talkative person B．a
well-informed witness
C．the
only person who was interviewed in the incident
D．a
person who watched the whole incident
59．Burton’s
final impression of the witness was that .
A．his
report was not clear though he was honest
B．he
was afraid of being involved and refused to help the police
C．his
observation was good but he was not very clear-headed
D．he
was a dependable and reasonable witness
B
The problem of
leisure is new. Until very recent times people worked each day to the limit of
their strength. Of course there were always a privileged (有特权的)few who had
leisure; but most men had to work 12, 14, or even 16 hours a day, six days a
week. As late as 1840 the average factory worker labored 72 hours a week.
"Sunup to sundown" was the farmer's day, or as another phrase puts
it, "from can to can't."
Today, working
less than a 40-hour week, people enjoy more leisure time. Therefore, the wise
use of leisure time has become an important problem for everyone, young or old.
It is a particularly difficult problem for the sick, the aged, and those who
have retired from earning a living. Those people have so much leisure that it
is hard for them to find interesting and worthwhile ways to use it .
However short the
work week becomes, work is still the most important part of life. We do not
work to get leisure and the pleasures leisure brings us; rather, we use leisure
wisely so that work itself can become awarding and enjoyable. The feeling of
success at doing one's daily work―whether it is a job, maintaining a home, or
going to school―depends largely on coming to it each day with fresh energy and
active interest.
Leisure and
recreation (消遗)go together, though they are not necessarily the same thing.
"Recreation" has an obvious meaning. It is the kind of leisure
activity that brings "re-creation" of strength and spirit. When one
speaks of making good use of leisure, he means choosing recreational activities
which contribute to health, growth, and spirit.
60.How to spend leisure time wisely is not a particularly difficult problem for
people _______.
A. who are very
busy everyday
B. who are sick
in bed
C. who are aged
and in good health
D. who have
retired from work
61.It can be inferred from the passage that _________ .
A. we work hard
so that we can enjoy more leisure.
B. we enjoy
leisure so that we can come back to work with energetically.
C. Leisure can
bring us a lot of pleasures that work can not.
D. The success
of work has little to do with how we spend our leisure time.
62. What is the relationship between leisure and recreation, according to the
author?
A. Leisure and
recreation are closely related.
B. Leisure and
recreation are the same.
C. Recreation
covers all kinds of leisure activities.
D. Recreation
does not belong to any leisure activity.
63. From the passage we know that __________.
A. leisure has
been an old problem since ancient times
B. leisure can
not be replaced as the most important part of life
C. our success
in work is mostly determined by whether we use leisure wisely
D. good
recreational activities can help improve health, growth and spirit
C
Buy now, pay
later. Credit cards give people that choice. Those billions of small pieces of
plastic in use all over the world make it easy to buy things. But people who
use credit cards unexpectedly can soon find themselves heavily in debt.
Cardholders may not think about it, but they borrow money from a bank or
other lender each time they charge something. They avoid interest charges if
they pay their bill in full each month. But if they only make the minimum
payment, the lowest required, it may take years to pay off a debt. Interest is
continually charged on the unpaid amount of money.
A credit card
may have a number of costs. First, there is the interest charge on purchases,
known as the annual percentage rate, or A.P.R. In the United States right now,
the average is between thirteen and fourteen to keep them. Cardholders may have
to pay cash advance fees if they withdraw (取) money from a credit card.
There are also fees if they go over their credit limit, or if a payment is
late. Lenders may also raise interest rates as punishment.
In the
United States, credit card fees have become a political problem. Congress has threatened
(威胁) to take action
against what critics call abusive behavior by lenders. Yet getting a credit
card has become a lot easier for most people. Maybe too easy: People receive
offers in the mail of pre-approved cards that they never asked for. Many cards
offer low rates at first, especially if people agree to move their balance from
another card, absolutely for free.
About half of all Americans have at least two credit cards. And the
credit rating agency Experian says fourteen percent of the population has more
than ten. Jeanne Hogarth at the Federal Reserve, the central bank, says the
average family has four credit cards. But families that carry a balance,
meaning they do not pay off their statements each month, have an average of
five.
In 1988 Americans had three
hundred thirty billion dollars in credit card debt. Last year it was eight
hundred forty billion. In the latest government study, the average credit card
debt for all households was more than three thousand dollars. But for those
that carried a balance, the average was five thousand three hundred.
64. Credit cardholders can prevent themselves from paying interest charges by
______.
A. putting more money into the
bank B.
paying cash advance fees
C. paying their bill in full each
month D. making the minimum
payment
65. Which of the following is NOT included in the costs of a credit card?
A.
A.P.R B. Going over the card limit.
C. Late
payment.
D. Moving balance from another bank.
66. We can infer from the text that _______ is/are seriously concerned about
what some lenders are doing with their credit cards.
A. the Federal
Reserve
B. cardholders
C. Congress D. the credit rating
agency Experian
67. Which would be the best title for this passage?
A. Credit Cards Are Easy to Get,
But Harder to Pay Off B. What Are Credit Cards
C. How to Apply for Credit
Cards
D.
Say No to Credit Cards
D
I'm usually
fairly skeptical about any research that concludes that people are
either happier or unhappier or more or less certain of themselves than they
were 50 years ago. While any of these statements might be true, they are
practically impossible to prove scientifically. Still, I was struck by a report
which concluded that today's children are significantly more anxious than
children in the 1950s. In fact, the analysis showed, normal children aged 9 to
17 exhibit a higher level of anxiety today than children who were treated for
mental illness 50 years ago.
Why are America's kids
so stressed? The report mentions two main causes: increasing physical isolation
―brought on by high divorce rates and less involvement in community, among
other things ―and a growing feeling that the world is a more dangerous place.
Considering that we can't
turn the clock back, adults can still do plenty to help the next generation deal
with it.
At the top of the list
is nurturing develop a better appreciation of the limits of individualism. No
child is an island. Strengthening social ties helps build communities and
protect individuals against stress.
To help kids build stronger
connections with others, you can pull the plug on TVs and computers. Your
family will thank you later. They will have more time for face-to-face
relationships, and they will get more sleep.
Limit the amount
of virtual(虚拟的) violence your children are exposed to. It's not just video
games and movies; children see a lot of murder and crime on the local news.
Keep your expectations
for your children reasonable. Many highly successful people never attended
Harvard or Yale.
Make exercise part of your
daily routine. It will help you deal with your own anxieties and provide a good
model for your kids. Sometimes anxiety is unavoidable. But it doesn't have to
ruin your life.
68. The underlined word skeptical could be best replaced by ______.
A. puzzled B.
doubtful C.
sure D.
curious
69. What does the
author mean when he says "we can't turn the clock back" in paragraph
3?
A. It's impossible to slow down the pace of change.
B. The social reality children are facing cannot be changed.
C. Lessons learned from the past should not be forgotten.
D. It's impossible to forget the past.
70. According to
an analysis, compared with normal children today, children treated as mentally
ill 50 years ago____.
A. were less isolated
physically B.
were probably less self-centered
C. probably suffered less from
anxiety D.
were considered less individualistic
71. The first and
most important thing parents should do to help their children is ____.
A. to provide them with a safer
environment B. to lower
their expectations for them
C. to get them more involved
socially
D. to set a good model for them to follow
72. What
conclusion can be drawn from the passage?
A. Anxiety, though unavoidable, can
be dealt with.
B. Children's anxiety has been a
huge problem since the 1950s.
C. Children's anxiety can be got
rid of with more parental care.
D. Anxiety, if properly controlled,
may help children become mature.
第二节 简答题（共3小题， 满分6分）
阅读下面短文，根据第73至第75小题的具体要求，简要回答问题。
Many cities
around the world today are heavily polluted．Careless methods of
production and lack of consumer demand for environment friendly products have
contributed to the pollution problem. One result is that millions of tons of
glass, paper, plastic, and metal containers are produced, and these are
difficult to get rid of.
However,
today, more and more consumers are choosing “green” and demanding that the
products they buy should be safe for the environment. Before they buy a
product, they ask questions like these: “Will this shampoo damage the
environment?” “Can this metal container be reused or can it only be used once?”
A recent
study showed that two out of five adults now consider the environmental safety
of a product before they buy it. This means that companies must now change the
way they make and sell their products to make sure that they are “green”, that
is, friendly to the environment.
Only a few years
ago, it was impossible to find green products in supermarkets, but now there are
hundreds. Some supermarket products carry labels to show that the product is
green. Some companies have made the manufacture of clean and safe
products their main selling point and emphasize it in their advertising.
The concern for
a safer and cleaner environment is making companies rethink how they do
business. No longer will the public accept the old attitude of “Buy it, use it,
throw it away, and forget it”. The public pressure is on, and gradually
business is cleaning up its act.
73. Find in the passage a word
closest in meaning to the underlined word “manufacture”.
74.Why
are companies rethinking how they do business? (回答词数不超过12个)
75. What
would be the best title for the text? （回答词数不超过4个）
第四部分 书面表达（共两节，满分35分）
第一节 填空（共10小题，满分10分）
阅读下面短文，根据所读内容在文后第76至第85小题的空格里填上适当的单词或短语。注意：每空不超过3 个单词。
Inflation refers to a rise in prices that causes
the purchasing power of a nation to fall. Inflation is a normal economic
development as long as the annual percentage remains low; once the
percentage rises over a
pre-determined level, it is considered an inflation crisis.
There are many causes
for inflation, depending on a number of
factors. For example, inflation can happen when governments print too much
money to deal with a crisis. As a result, prices end up rising at an extremely
high speed to keep up with the extra money. This is called the demand-pull, in
which prices are forced upwards because of a high demand.
Another common cause of inflation is a rise in production costs, which
leads to an increase in the price of the final product. For example, if raw
materials increase in price, this leads to the cost of production increasing,
which in turn leads to the company increasing prices to maintain steady
profits. Rising labor costs can also lead to inflation. As workers demand wage increases, companies
usually chose to pass on those costs to their customers.
Inflation can also be caused by international
lending and national debts. As nations borrow money, they have to deal with
interests, which in the end cause prices to rise as a way of keeping up with
their debts. A deep drop of the exchange rate can also result in inflation, as
governments will have to deal with differences in the import/export level.
Finally, inflation can be caused by federal taxes put
on consumer products such as cigarettes or fuel. As the taxes rise, suppliers
often pass on the burden to the consumer; the catch, however, is that once
prices have increased, they rarely go back, even if the taxes are later
reduced. Wars are often cause for inflation, as governments must both pay back
the money spent and repay the funds borrowed from the central bank.
War often affects everything from international trading to labor costs to
product demand, so in the end it always produces a rise in prices.
Title:
76
第二节 写作（满分25分）
假若你叫张华，是湖南某中学一名高中学生。今年暑假，你的美国笔友David计划来中国，并有意在你家居住。请你根据以下提示给他回一封信。
信中应包括以下要点：
1. 表示欢迎。
2. 对你们这几天的活动安排提出至少三条建议。
注意:
1. 词数: 120左右。
2. 不能写成诗歌形式；不能使用真实姓名和学校名称。
3. 信的格式已经为你写好。
英语答题卡
听力填空：
18.
________________________________
19.
________________________________
20.
________________________________
简答题：
73.
____________________________________________________
74.
____________________________________________________
75.
____________________________________________________
阅读填空 （请用0.5毫米黑色墨水签字笔书写）
76. ___________________________ 77.
__________________________
78. ___________________________ 79.
__________________________
80. ___________________________ 81.
__________________________
82. ___________________________ 83.
__________________________
84. ___________________________ 85.
__________________________
书面表达 （请用0.5毫米黑色墨水签字笔书写）
May 10
Dear David,
Yours
Zhang
Hua
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While most teenagers earn the
minimum wage from weekend jobs, Jonathan Grubin, a
16-year-old boy, has logged on to an online success which turned over ￡ 75,000 last year.
2．潮间带常见的浜螺捕食多种藻类，尤其喜食竞争力强的浒苔。据图1判断下列叙述不正确的是（ ）
A．五种元素一定都是非金属元素
2Z(g)，
16．如图2 （甲）所示是用沙摆演示振动图象的实验装置，此装置可视为摆长为L的单摆，沙摆的运动可看作简谐运动，实验时在木板上留下图（甲）所示的结果。若用手拉木板做匀速运动，速度大小是0.20 m/s。图（乙）所示的一段木板的长度是0.60 m，那么这次实验所用沙摆对应的单摆长L约为
17．向心力演示器如图3所示。转动手柄1，可使变速塔轮2和3以及长槽4和短槽5随之匀速转动。皮带分别套在塔轮2和3上的不同圆盘上，可使两个槽内的小球分别以几种不同的角速度做匀速圆周运动。小球做圆周运动的向心力由横臂6的挡板对小球的压力提供，球对挡板的反作用力，通过横臂的杠杆使弹簧测力套筒7下降，从而露出标尺8，标尺8上露出的红白相间等分格子的多少可以显示出两个球所受向心力的大小。现分别将小球放在两边的槽内，为探究小球受到的向心力大小与角速度的关系，下列做法正确的是（ ）
19．图5是质谱仪工作原理的示意图。带电粒子a、b经电压U加速（在A点初速度为零）后，进入磁感应强度为B的匀强磁场做匀速圆周运动，最后分别打在感光板S上的x1、x2处。图中半圆形的虚线分别表示带电粒子a、b所通过的路径，则（ ）
A．铁块与轻弹簧相碰过程中所具有的最大弹性势能
（1）（6分）某同学利用双缝干涉实验装置测定红光的波长，已知双缝间距d=0.20 mm，双缝到屏的距离L=700 mm，将测量头的分划板中心刻线与某一亮条纹的中心对齐，并将该条纹记为第一亮条纹，其示数如图7所示，此时的示数为_______mm。然后转动测量头，使分划板中心刻线与第五亮条纹的中心对齐，测出第五亮条纹与第一亮条纹中心线间的距离为9.240 mm。由以上数据可求得该红光的波长为_________m（保留两位有效数字）。
①采用如图8所示的电路测电流表G的内阻Rg，可选用器材有：
设电流表G内阻Rg的测量值为R测，真实值为R真，则R测____________R真。（填“大于” “小于”或“相等”）
29．（12分）小麦籽粒中的糖类，主要依靠穗下第一张叶片（旗叶）的光合作用供给，其他绿色部分如麦穗也有光合能力。图17示小麦旗叶和麦穗光合作用与耐旱性关系的研究结果。请回答下列有关问题：
31．（18分）控制人血红蛋白的基因分别位于11号
（4）图19是一个镰刀型细胞贫血症的系谱图。由此可
14．（本题满分7分）
某文具店销售的学生用地球仪只有A，B，C三种型号，下面表格和统计图分别给出了上月这三种型号地球仪每个的利润和销量。
的中点，DE⊥AC于E。求证：DE是⊙O的切线。
，0），动点P，Q同时从O点出发，P沿折线OACB方向运动，Q沿折线OBCA方向运动。
⑶若P的运动速度是每秒1个单位长，Q的运动速度是每秒2个单位长，运动到相遇时停止，设△OPQ的面积为S，运动时间为t秒，S与t之间的函数关系式。
