Astronauts must take a series of tests to see whether they are capable of living in space.
举一反三
- Astronauts are connected to the space shuttle so that they cannot float off into space.
- Why do people have to take a series of tests in the passage In order to get （）.
- Generally speaking, there are four categories of space. They are intimate space, personal space, _______ space, and public space.
- The___worn by astronauts is designed to keep them alive in outer space.
- Astronauts now ____________: Pilots, the astronauts who actually fly the space shuttle, account for one-third of the astronaut