Listen carefully in class, you’ll not understand what to do.
Can you describe the people and the things ______ have been seen in Tibet?
Now it’s nearly half past six, and we have a little time ______ to catch the last bus.
I heard from my pen pal yesterday, but I haven’t replied ______ her.
Did you know ______?
The number of people invited _____fifty, but a number of them ______ absent (缺席) for different reasons.