You can never be ________ when crossing the street．
| A．very careful | B．too careful |
| C．carefully enough | D．enough careful |
His wife left him, because he was in such heavy debt _________ he could never __________.
| A．as...pay off | B．that… pay back | C．as…pay for | D．that…pay in |
Do remember to remind her_________the gas before she leaves.
| A．of turning off | B．to turn off | C．turning off | D．turn off |
Last summer holiday, I went back to my hometown, ________ the neighbours and the house ________ I used to be familiar with were gone.
| A．only finding; which | B．only to find; that |
| C．to find; whom | D．found; that |
Nuclear science should be developed to benefit the people ______ harm them.
| A．more than | B．rather than | C．other than | D．better than |
—May I smoke here?
—If you ________, choose a seat in the smoking section.
| A．should | B．could | C．may | D．Must |