问题 填空题

如图表示一交流随时间变化的图像,此交流的有效值为             A。

答案

5A

根据热效应相等可列的等式,即,解得电流的有效值为5A

故答案为5

阅读理解

You may know the song Happy Birthday very well. But do you know who wrote this song and for whom it was written? Let me tell you a story. About one hundred years ago, there was a girl called Kate in the USA. She loved children very much and wrote many songs for children. One of them was the song Good Morning To You. The song was very popular at that time among children, but not all grown-ups ( 成年人 ) knew it.

The girl was very poor. Once her friends invited her to a little child's birthday party. She felt happy but sad because she had no money to buy a present for him. Finally she decided to sing the song Happy Birthday. in the melody (曲调) of Good Morning to You for the little boy. When her friends heard the song at the party, they were very happy. "How wonderfully she is singing!We have not heard this song before. It's a special present," said someone. And they learned to sing it together. Later, the song became very popular throughout the world. People like it because it's simple and friendly. 

判断下列句子是否与短文内容相符,相符的填“T”,不相符的填“F”。

小题1:Happy Birthday is a old song. Nobody knows who wrote the song Happy Birthday.

小题2:The song Happy Birthday is a song from America.

小题3:The melody of Happy Birthday comes from the melody of Good Morning to You.

小题4:The girl first sang the song for a little child as a birthday present.

小题5:The girl knew the song would be popular before she came to the party.

单项选择题 A1/A2型题