20.—Though it is 30 years _____ we last met, I still remember the scene _____ we got separated on a rainy day.
Don’t wake Doctor Thompson up unless it is a real_________; he is too tired and needs a good rest.
---The girl looks so beautiful. Is she a model or a film star? ---________. She’s a teacher.
The knowledge ____ in one’s childhood will make a stronger impression on him than what he learns at any other life stage.
In China today, _______ car is becoming _____ popular means of transportation.
--- You hate Lee, don't you? ---______I just think he is a bit annoying.