While the alien ________ the museum, the boy called the TV station.

What ________ you ________ at this time yesterday?

RT-Supermarket _______at 9 a.m. and it ______ for 10 hours every weekend．

What was he doing ______ his father _______ back?
A. while; came          B. when; came              C. when; was coming

—I used to be quiet but now I’m very outgoing.
—Oh, you __________ a lot.

I don’t know if she___________. If she __________, please let me know.

---Where is your grandpa?
---He _________ Canada and __________ Toronto for a month.

My brother usually _____ his classroom after school. But now he _____ basketball.

The number of foreign students attending Chinese universities ________ rising steadily since1990. 

--- What did your daughter say in her letter?
--- She told me that she ________ Cambridge University already with her friends.