He waited until it was dark ____ nobody could see him clearly.
| A．so that | B．in order to | C．although | D．However |
In my old school album there are some pictures of some teachers ______ can’t be found in yours．
| A．which | B．who | C．those | D．they |
Now teenagers like to go to the fast food restaurants, ______ eating doesn’t take much time．
| A．which | B．who | C．what | D．where |
For weeks the street hasn't been cleaned by the cleaners, _____ makes it very dirty．
| A．who | B．which | C．that | D．this |
The artist ______ the judge gave a prize is the teacher _____ I have been taught painting for two years．
| A．from whom; by whom | B．to whom; who |
| C．from whom; who | D．to whom; by whom |
You were very impolite to him, for ______ you should make an apology to him, I think,
| A．this | B．which | C．what | D．that |