根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

Policeman: Now, Jimmy, did you get a good view of the accident?

Jimmy: Oh, yes. I was standing outside the bank building and I saw it quite clearly.

Policeman: Do you know what time it was?

Jimmy: Yes. ____ It was 2:45 exactly.

Policeman: Good. ____

Jimmy: Well, quite slowly --- about 10 miles an hour. It was coming up York Road. ____ But they were still red when he went over them.

Policeman: I see. ____ was it also driving slowly?

Jimmy: It was coming along Union Street about 30 miles per hour. It was a blue Toyota. ____

Policeman: Did you see what colour his traffic light was?

Jimmy: Yes, it changed to yellow just before he crossed it.

A. What about the car?

B. I checked my watch.

C. Didn't you see the car?

D. Now, how fast was the truck moving?

E. Was the car going beyond the speed limit?

F.I suppose(猜想) the truck driver knew the lights were going to change.

G. The driver stopped his car when he saw the truck crossing the street.

关于空气的组成，从下列实验中你能得出什么结论？

老花镜的“度数”等于它的焦距的倒数乘100，请设计一个测老花镜度数的简单方法，要求写出所用器材、操作步骤和计算公式。