Our government has promised to improve our water quality, so it won’t be long _______ the residents can have access to clean water.
| A．after | B．since | C．before | D．unless |
That tree, __________ are almost bare, is a very old one.
| A．whose branches | B．the branches of which |
| C．of which the branches | D．All of the above |
The reason ____ she was absent is _____ he was badly ill yesterday.
| A．why; that | B．why; because |
| C．for which; because | D．that; because |
It suddenly _____ to the detective that the professor was probably murdered by his own wife .
| A．occurred | B．came about | C．took place | D．Happened |
---What made her unhappy?
---_____.
| A．Because she lost her wallet | B．she lost her wallet |
| C．Losing her wallet | D．To lose her wallet |
The machine might break down someday in the future, ____, you can dial this number for help.
| A．in that case | B．in what case |
| C．in which case | D．in whose case |