In order not to disturb his research,his wife__________the news of her sickness.[ ]

Speak to him slowly________ he may understand you better.

Haven’t I seen you some place before?—Yes. That’s ________ I don’t go there anymore.

Was it in 1969 _______ the American astronauts succeeded ______ landing on the moon? [ ]

I have been told that our visit to Mount Tai will be cancelled because a very important foreign delegation (代表团) will be there.—-Oh, no！______.