We do not know how astronauts can ________ when they spend months in space without the protection of the atmosphere.

ire is a strict but kind teacher, _____ I respect and appreciatemost.

Hi, Jake, long time no see. How is _____going —Not bad.

Betty is in Jinan her parents.

No matter how you read it, this sentence just doesn’t make sense-the most important words have been ________. [ ]