I have been living in the United States for twenty years,but seldom _______ so lonely as now.

---_______ one and a half months enough for the project to be finished?　　---I am afraid not. The professor is ill and only after he recovers ________ go on with it.

Only by learning more about different cultures _______ avoid misunderstanding during international cooperation.

At the meeting place of the Yangtze River and the Jialing River     , one of the ten largest cities in China.

 ---How was the weather then? ---Hardly _____ off the plane when it started to rain.