介词的主要分类：
1. at the cinema, in the hospital __________
2. Write with a pen, go by bus ___________
3. in summer, on September 1st ___________
4. laugh for joy, be angry at his words________
5. by the way, at last, in the end _________
地点介词
方式介词
时间介词
固定搭配
原因介词
其他介词...
