Good table manners

    We are going to hold a talk on good table manner. The purpose of the talk is to teach students

根据括号内的汉语提示，完成句子。(每空一词)
The young man found it difficult to have dinner because some of his ____ (牙齿)had been pulled out.
Tom and Linda have been____ ( 结婚) for ten years, but they've never quarreled.
If you want to become a good Marathon athlete, you must practice ____ (跑步) every day.
He manages over 100 big companies, He is considered to be one of the most ____ (成功的) businessmen in China.
Their answers to the question were not the same, that's to say, they answered the question____ (不同地).
When you communicate with your American e-pal on the internet, the e-mails are supposed to be____ (写) in English.

投影仪是教学常用仪器，如图是投影仪的结构图。在水平放置的凸透镜正上方有一个与水平面成45°角的平面镜，右边竖直放一屏幕。物体发出的光线经过凸透镜和平面镜后，可在屏上成一清晰的像。老师在使用投影仪时，发现屏幕上的画面太大，请你帮助老师调节一下。

关于半导体，以下说法错误的是(       )