The place has a microgravity environment. Astronauts live and conduct research here

A. mistakes

C. changes

A. simple – simplicity

B. simplicity – simple

C. simplified – simplicity

A. After the USA put the first human on the moon, Russia had already sent the first human into space.

B. Before the USA put the first human on the moon, Russia had already sent the first human into space.

D. The USA put the first human on the moon before Russia had already sent the first human into space.

A. Ø – the

B. the – the

C. the – Ø

D. take

A. Quang, whom lives next door plays the piano very well.

B. Quang, whose lives next door plays the piano very well.

C. Quang, that lives next door, plays the piano very well.

D. Quang, who lives next door, plays the piano very well.