--- Hasn’t Zhao Wei finished filming the movie So Young?--- Yes. She ______ on it for more than half a year.

 Tim, ______ you ______ your homework yet?

—Haven't I told you that you should be home earlier?—Yes, but I________home earlier than I usually do. 

By the time Pierce comes back from the meeting，we________here for three hours.

Unfortunately, when I dropped in, Professor Smith ________, so we only had time for a few words.