The girl has a great interest in sport and ____ badminton classes twice a week over the last three years.

In the meeting, the professor expressed his thanks for the aid he _________ from his students.

I would have come earlier, but I _____ that you were waiting for me.

Liu Ming is said         abroad for one year before he came to teach in our school．

— Why do you look so worried? —My computer broke down and my essay ______ unfinished since.