[10-20 18:09:40] 来源：http://www.67xuexi.com 初二英语 阅读：85440次
2.在there be结构中。如：
There is a boy swimming in the river.
3.在have fun/problems结构中。如：
We have fun learning English this term.
They had problems getting to the top of the mountain.
4.在介词后面。如：
Thanks for helping me.
Are you good at playing basketball.