tom's mother needed__at once

问题描述:

tom's mother needed__at once
___made him worried.
a.operating on ,that.
b.operating on,which.
c.operating,that.
d.being opreating,which.
为什么不能用being operated ON呢?

need want require 等表示“要求 需要”之意的动词,如果表达的是“某是需要被做”时,后面加doing 或to be done