用所给词的适当形式填空:I saw them (play)football when I went past the playground at 4:00 this afternoon.

问题描述:

用所给词的适当形式填空:I saw them (play)football when I went past the playground at 4:00 this afternoon.

palying
下午四点我经过操场时,看到他们正在踢足球.