Astronauts are ________ to all kinds of tests before they are actually sent up in a spacecraft.
举一反三
- Astronauts should be very strong in health, so they are ________ all kinds of tests before they are finally sent up in a spacecraft.
- Up till today, our society ______ by all kinds of problems.
- Astronauts now ____________: Pilots, the astronauts who actually fly the space shuttle, account for one-third of the astronaut
- 8. “It was the first time that US astronauts were sent into space from US soil after a nine-year gap.” No US astronauts have ever been sent into space before.
- Astronauts must take a series of tests to see whether they are capable of living in space.