Loulan is believed __________ over by sandstorms gradually from AD200 to AD400

Our teacher has a _____ for thinking up ways _____ his speeches attractive.

Did your parents go to the meeting yesterday, Tom—Yes, _______ of then did, but _______ spoke.

Mother shut the window ______ she might keep the insects out

I go and buy more fruit for the party– No, I have already bought 3 baskets. That ____ be enough.