_____ life will continue on the earth for millions of years to come will depend on ______this problem can be solved.
| A．Whether; that | B．That; why | C．Thathow | D．Whether; whether |
Cleaning women in big cities usually get ____by the hour.
| A．pay | B．paying | C．paid | D． to pay |
It is about time that he ______ to supper, for he still has a meeting to attend this evening.
A goes B went C has go
ne D go
Only when class began ______that he had left his book at home．
| A．will he realize | B．he did realize | C．did he realize | D．had he realized |
They will fly to Washington, ______they plan to stay for two or three days.
| A．which | B．where | C．there | D．when |
The explanation of our teacher will make the reading easy ______.
| A．to be understand | B．to understand | C．understood | D．understanding |