There ___ life on the earth for hundreds of millions of years.A. has been B. is having C. have been
Mary is really good at taking notes in class. She can almost_______every word the teacher says.
I know this plan is far from perfect. But I really can’t think of ______one.
I really found it difficult to read, for his eyesight was beginning to________.
----What are you busy doing these days? ----I______ study for the coming exam.
----You needn’t take an umbrella. It isn’t going to rain. ----Well, I don’t know. It_____do.