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)shaving corrected 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。