I'll return the book to the library as soon as I________it.
| A．will finish | B．am going to finish |
| C．finished | D．have finished |
These increased harvests _____ that 22% of the world’s people are fed from just 7% of the farmland in China.
| A．means | B．meant | C．mean | D．is meaning |
Some people have the idea_____ you can cross Canada in less than five days.
| A．what | B．that | C．which | D．when |
Only after her mother came to help her for the first few months ______ to begin her project.
| A．did she allow | B．had she allowed |
| C．was she allowed | D．is she allowed |
Thanks to Dr Yuan’s research, the UN has more tools in the battle to rid the world _____ hunger.
| A．of | B．on | C．off | D．at |
______ is even more important is that the earth cooled down, water began to appear on its surface.
| A．When | B．That | C．Which | D．What |