1.How many hours of (fly) experience does one need to become an astronaut?
答案flying
2.Yang Liwei is one of the most famous (astronaut) in the world.
答案astronauts
3.It has been proved that mental health is related physical health.
答案to
4.My writing style is similar that of my brother’s.
答案to
5.Do you know who is the first woman astronaut (go) into space?
答案to go
