．It was the four years from 2004-2007, ____ I spent studying for a master’s degree, ____ I will never forget．
| A．when; that | B．when; when | C．that; that | D．which ; that |
Not long after his return, a local war ____ near his town.
| A．broke in | B．broken into | C．broke out | D．broke down |
Later, these rocks proved that ___ in the distant past the Antarctic was covered by plants.
| A．at one time | B．at a time | C．at times | D．at the same time |
The prisoners then wrote the stories in a book called “The Description of the World”, ____ became one of the best-selling books in Europe.
| A．it | B．which | C．that | D．where |
Could you help me to find out the reason ____ the brake doesn’t work?
| A．when | B．how | C．why | D．in which |
Eric the Red was forced to leave because he had committed a murder, ____ he got into trouble.
| A．for which | B．where | C．to which | D．why |