I really don’t know _______ I put my wallet.
| A．where was it | B．it was where that |
| C．where it was that | D．where was it that |
If you ______ talk about it with me, please wait till I finish my work at hand.
| A．can | B．may | C．must | D．should |
Because they usually receive the same score in the exams, there’s often disagreement as to ______ is the better student, John or Mary.
| A．whom | B．which | C．that | D．what |
Some of the drivers were ______ by the police because of their good behavior in the traffic accident.
| A．examined | B．questioned | C．praised | D．punished |
Bad habits, ______ formed(形成), are difficult to give up.
| A．and | B．once | C．for | D．but |
These natural parks are very important for preserving many animals, which would ______ run the risk of becoming extinct(灭绝的)．
| A．otherwise | B．other than | C．therefore | D．in another way |