NASA(National Aeronautics and Space Administration）will start a new search for astronauts to go on future space tasks. This is part of the plan to make people live on Mars within the next 20 years. 1. ______
You've got to be smart.
In order to be an astronaut, you have to study subjects like Science, Maths or Engineering at university so that you can do experiments in space and then send back the results to scientists on the Earth. 2. ______
You've got to be physically strong.
Living in space may cause all kinds of problems for the human body. 3. ______ After five months in space above the Earth, an astronaut may typically lose as much as 40％ of muscles. Astronauts have to exercise in space to keep their muscles active.
During blast - off(发射）, astronauts can experience great force of gravity pressing down on them. 4. ______
You've got to be brave.
Spacemen and spacewomen have to go through some very hard training before they become astronauts. Scientists have to be sure that the trainee is strong enough both physically and mentally to live and work in space. 5. ______ As part of their job, astronauts might need to go to new places which humans have never been to before, so they need to be brave.
A. So what does it take to be an astronaut?
B. Muscles are very important for the body.
C. For example, you may lose some of your muscles.
D. They have to be physically strong to deal with this.
E. It is looking for men and women between 157 cm and 190.5 cm.
F. A good education also helps astronauts understand how to fix things in the spaceship.
G. They may get lonely when they are far away from their family members, so they have to be mentally strong.

1~5. AFCDG