《2025年桂壮红皮书暑假天地河北少年儿童出版社八年级英语》

五、完形大练兵
Look at your computer keyboard. Have you ever wondered ____21____B the letters are not in alphabetical(字母的) order?
To answer this question, let’s turn the clock back. About 150 years ago, people wrote all letters and papers by hand. That was ____22____A. Later, some inventors produced typing machines. The first typewriters(打字机) were big and heavy. They worked ____23____C a piano.
Have you ever seen the inside of a piano? You press a key and some levers(杠杆) will make a hammer(音槌) hit the right string(弦) to ____24____D a sound. Early typewriters were similar. They had many levers. At the end of each lever, there was a letter. One ____25____A the A key and the A lever would hit the paper and type A. The paper then ____26____B a bit to the left. One pressed more keys and he could type a word or even a book.
The first typewriters had the ____27____D in alphabetical order. There was a problem: If one pressed two keys quickly, the levers would ____28____D become unable to move.
To ____29____A this problem, people tried to change the positions of the letters. An American inventor invented the QWERTY keyboard. It turned out to be a great ____30____A. People around the world began to learn to use the keyboard.

答案： 21.B 22.A 23.C 24.D 25.A 26.B 27.D 28.D 29.A 30.A