Is oxygen the only gas _______ helps fire burn?
| A．that | B．/ | C．which | D．it |
Christmas is _____special holiday when _____whole family are supposed to get together.
| A．the; the | B．a; a | C．the; a | D．a; the |
—He must be in the reading-room now. We will find him there.
---No, he _____.Tom said he was ill at home .
| A．must not | B．can’t | C．may not | D．should not |
___ some teenagers don’t realize is ___ difficult life can be after they get addicted to drugs.
| A．What；how | B．What；what | C．That；how | D．That；what |
Among Asimov’s most famous works of science fiction, one ______he won an award, was the Foundation Trilogy.
| A．of whom | B．of which | C．for whom | D．for which |
When I approached to the subway entrance, an explosion occurred. This ___my first experience, I got into panic
| A．was | B．is | C．being | D．been |