Whether life will continue on the earth will depend on _______ this problem can be solved.
| A．that | B．which | C．whether | D．If |
This church is as old as, if _____ than, that one.
| A．no older | B．not older | C．no old | D．not old |
Her pronunciation is as good as, if ____than, her teacher's.
| A．no better | B．not better | C．no good | D．not good |
In that month, he earned as much as, if ____ than, $40 000.
| A．no more | B．not more | C．no much | D．not much |
The research is so designed that once _____ nothing can be done to change it.
| A．begins | B．having begun | C．beginning | D．begun |
If _____ carefully, the experiment will be successful.
| A．do | B．does | C．done | D．doing |