while doing sth 省略什么 为什么
while doing sth 省略什么 为什么
by doing sth.可以省略by吗?
when while and see sb doing sth
while I was doing可省略I was吗
keep sb.from doing sth.和stop sb.from doing sth.中哪个from可以省略
succeed in doing sth 中 in可以省略吗?
stop sb from doing sth 中from可以省略吗
succeed in doing sth 的in可以省略吗?阿
assist sb in doing sth中in可否省略?
join sb in doing Sth 中的in可省略吗:-).
Help sb in doing sth中的in可以省略吗?
succeed in doing sth.这里的in能不能省略?