题目

Happy Time is a program on ABC Radio. John Brown is an announcer (播音员) for the program. Most of the girls and boys like the program. They also like John Brown. Some of them often make calls to him and thank him for his work. There are lots of letters(信件) to him every day, too． John Brown gets up at 6:00 every morning. He leaves home at 6:30 and gets to his office at 7:15. The program begins fifteen minutes later. He always plays some new songs and music for his listeners.John finishes his work at 6:30 in the evening. He goes home in his car. He likes reading newspapers and listenin某同学使用的显微镜有如下一些镜头可供选择，要使被观察的物体放大50倍，应选择的镜头为 A.④和⑤；       B.①和③；      C.③和⑥；          D.②和⑥。