_____ three influenza type A virus subtypes(子类型) have been found in pigs.
| A．By far | B．As far as | C．So far | D．Till far |
Let us not waste ______ time we have left .
| A．the little | B．little | C．a little | D．a little more |
Do you consider it any good _____ the truck again ?
| A．to repair | B．repairing | C．repaired | D．being repairing |
It's nearly seven o'clock . Jack _____ be here at any moment .
| A．must | B．need | C．should | D．can |
If you _____ stop smoking , you can only expect to have a bad cough .
| A．won't | B．would not | C．do not | D．can not |
.—Must I turn off the gas after cooking ? --Of course . You can never be ___ careful with that.
| A．enough | B．too | C．so | D．very |