在表示一个被动动作时，如果这个动作正在进行，或是与谓语表示的动作同时发生，我们可以用现在分词的被动形式。
【例如】
The bridge being built now will be completed in three months.This is one of the experiments being carried on in our laboratory.
Being surrounded by the students, the teacher was answering questions one by one.
If I correct someone, I will do it with as much good humor and self-restraint as if I were the one ____. (CET-4 1996,6)
A) to correct B) correcting C)shavingscorrected D) being corrected
句意为：如果我批评某个人，我会尽量保持幽默，自我控制，像批评自己一样。one为代词，后面的动词为其修饰成分，故用分词，而且one与correct之间是动宾关系，故用分词被动式，答案为D。
