《2025年英语同步练习与测评高中英语必修1外研版青海专版》

<题目>阅读短文,按照题目要求用英语回答问题。
A
Feathers are not just for flight. They keep birds warm, become part of their nests, and help them attract mates (配偶). And for one Australian bird, feathers even help produce an important sound as an alarm. "People had long noticed that some birds produced these loud whistles," Trevor Murray, a researcher at the Australian National University said. His teacher Rob Magrath and May Hingee thought these sounds were used as an alarm. So they did some playbacks and they could show quite strongly that if people played back these sounds to other birds, they fled (逃走) straightaway. So Murray was really interested in how they produce the sound, and whether it's a reliable signal.
The team focused their experiment on specific feathers in the crested pigeon's wing. They were able to target the eighth primary feather, which is unusually narrow - it's about half the width of the surrounding feathers. And then they also removed, on different sets of birds, those neighbouring feathers, the ninth primary feather and the seventh primary feather. They were able to see that when the eighth primary feather was missing, the high note completely disappeared. So the eighth primary feather produced that high note.
And if the birds are fleeing from dangers, they produce a louder and higher whistle than they do during a normal takeoff. Murray and his colleagues did another experiment where they used the recordings they made to observe the reactions of other crested pigeons. From the experiment they found that the eighth primary feather, the unusual feather, played a crucial role in signaling alarms. When that eighth primary feather was missing, the pigeons very rarely responded. They almost never fled.
1. What are the usual functions of birds' feathers? (no more than 25 words)Birds' feathers are for flight and they can also keep birds warm, become part of their nests and help attract mates.
2. Why did Rob Magrath and May Hingee think the long whistles some birds produced served as an alarm? (no more than 15 words)Because when they played back these sounds to other birds, they fled away.
3. Which feather produced the whistle? (no more than 8 words)The eighth primary feather.
4. What does the underlined word "crucial" in the last paragraph probably mean? (1 word)Key.
5. What is the conclusion from the experiment according to the last paragraph? (no more than 15 words)The eighth primary feather, the unusual feather, played a key role in signaling alarms.

答案： 1. Birds' feathers are for flight and they can also keep birds warm, become part of their nests and help attract mates.
2. Because when they played back these sounds to other birds, they fled away.
3. The eighth primary feather.
4. Key.
5. The eighth primary feather, the unusual feather, played a key role in signaling alarms.