问题 填空题

碘钨灯是一种新型电光源,一种照明用的碘钨灯工作电压是220V,额定功率是100W.该灯正常工作时,以通过灯为电流为______A;每秒消耗的电能是______J.

答案

I=

P
U
=
100
220
A=0.45A.

W=Pt=100×1J=100J.

故答案为0.45;100.

阅读理解

Last Sunday the Greens went to climb the hill. When they got home, it was very late. Mr. Green opened the front door and they both went into the house. Because it was too late, Mrs. Green turned on the light. Just they wanted to come into the bedroom, Mrs. Green suddenly said, “ Listen, there is someone in our bedroom.” They stood quietly outside the door. They could hear some voices in the room.

“There are two men in it. They are talking.” So Mr. Green began to shout. “Who is there?” But no one answered. Mr. Green opened the door quickly and turned on the light. There was no one there. Mr. Green found something and laughed. The radio was still on! “I forgot to turn it off this morning.” Mr. Green said.

根据短文内容选择正确答案。

(      ) 1. The Greens went home             .

A. in the morning  B. in the afternoon  C. in the evening  D. in the middle night

(      ) 2. They went into the house from             .

A. the door        B. the front door  C. the back door        D. the side door

(      ) 3. Mrs. Green heard someone talking             .

A. when she gets into the bedroom   B. when she was on the way to the bedroom

C. when she gets into the living-room   D. when she gets into the house

(      ) 4. There were               talking in the bedroom.

A. two women   B. a man and a women   C. two men     D. three men

(      ) 5. The people talking in the bedroom were             .

A. thieves  B. writer’s relatives C. writer’s good friends  D. speakers in the radio

单项选择题