问题 选择题
如图所示,理想变压器原、副线圈的匝数比为10:1,b是原线圈的中心接头,电压表V和电流表A均为理想电表.从某时刻开始在原线圈c、d两端加上交变电压,其瞬时值表达式为u=220sin100πt(V).下列说法正确的是(  )

A.当单刀双掷开关与a连接时,电压表的示数为22V

B.当单刀双掷开关与b连接时,电压表的示数为11V

C.当单刀双掷开关与a连接,滑动变阻器触头P向上移动的过程中,电压表的示数不变,电流表的示数变大

D.单刀掷开关由a扳向b时(滑动变阻器触头P不动),电压表和电流表的示数均变大

答案

答案:D

改错题
阅读理解

The holiday is coming to us. Finally, after months of study, you have some time to yourself. So, why not read a book? Well, some people will say, “Why do you like reading books? We have Internet. It offers a lot of more colorful fun. Books are history!” But I am sure you can learn a lot from books than Internet.

One clear reason is that a well-chosen book can give you a lot of wonderful  words, as long as you have a good dictionary, of course. Believe me; it’s far easier to get new words from a book or an article than it is from the TV or the Internet.

But another more important point is that books give you something that the Internet cannot. The general webpage (网页) is picture-heavy and the text is as easy to read as possible. While “easy” may attract (吸引) you, unluckily it’s not helpful for any long-term development of reading skills and the general language level. Because of that, reading on the Internet can’t take the place of reading books.

But perhaps the best reason is that just choosing what you read and doing it independently means that it’s something you do by and for yourself. You can choose what you want to read. It’s hard work, but you’ll find that what once seemed like a duty is now a pleasure.

小题1:Does the writer advise people to read books in their holidays?

小题2:What can people get from a well-chosen book?

小题3:What’s the general webpage like?

小题4:How many reasons for reading a book does the writer mention in the passage?

小题5:What does the writer want to tell us in the passage?