题目

So far, the air ___________ really polluted around here. I’m really ___________ worried.A. has become; getting                    B. have become; getting   C. has been becoming; got              D. has been becoming; got 答案：A   前半句So far提示用现在完成时，根据句意，后半句用现在进行时。比较sin31°、cos58°、tan32°三者的大小．