关于while
问题描述：
关于while
11.My sister __________( sing ) while my brother _________( play ) games.
12.The young man ___________( excite ) while ________( make ) a speech in the park.
可以说明一下关于while前后动词怎么用吗?
答
is singing is playing
is excited making
第一句,while前后都要用进行时（过去进行时也可）
第二句,前面一个格,用系表结构,后面用非谓语,或者he is making,可以省略he is