Something must be done to prevent factories sending out poisonous gases so as to keep the city _________.A polluting B. from polluting C. pollute D. from being polluted
. —May I see your ticket, please? I think you ________ in my seat. —Oh, you’re right. My seat is upstairs. I’m terribly sorry.
. . If Mary carries on working like this, she will ______ sooner or later.
. _____ the book where it was ______.
. She couldn’t ______ the fact that the money was found in his house.
. Your essay is too long. You’d better _______ to about 1000 words.