I didn’t see you when I went to your office yesterday afternoon. Where were you?—I ____ a meeting in the meeting room.
What time do you usually a shower,Rick?
Jack felt nervous when he found the physics problems ____ to work out.
Did you visit the 23rd National Books Expo last month?–Yes, it was really ______. We saw many famous people, like Mo Yan, Ni Ping and Yu Dan.
Look, Tina is waiting _______ the bus stop. [ ]