She ... a living as a part-time secretary.

A. earned  B. got  C. had  D. took

I love my family so much. They have always been extremely ... to me.

A. mature  B. realistic  C. supportive  D. known

Experiencing microgravity on a ... flight is part of astronaut training program.

A. parabol  B. parabola  C. parabolic  D. parabolically

One of the largest ... found on Earth is the Hoba from southwest Africa, which weighs about 54000 kg.

A. meteorites  B. meteoric  C. meteors  D. meteorite

In 2015 NASA discovered an Earth-like planet which might be ... because it has "just the right" conditions to support liquid water and possibly even life.

A. inhabited  B. inhabitants  C. habitable  D. uninhabited

It is cheaper to build an unmanned ... than the one that is manned.

A. space  B. spacecraft  C. spacious  D. spaciousness