副词
1. Please come in. 请进。
2. I called on him; but he wasn't in. 我去拜访他,但他不在家。
介词
1. In which direction did he go? 他朝哪个方向去了?
2. There is a pencil in the box. 匣子里有一枝铅笔。
3.
3. One child in twenty has this disease. 二十个小阿中有一个患有这种疾病。