After the big earthquake in Chile, there were about 300 aftershocks in the nearby area, ______ over 200 were quite damaging.
| A．which | B．of which | C．during which | D．whose |
What an unforgettable experience ！ I'll write it down __________ it is still fresh in my memory.
| A．since | B．while |
| C．after | D．until |
__________，many people go in for them and benefit from them.
| A．However some sports are challenging |
| B．However challenging some sports are |
| C．No matter how challenging are some sports |
| D．No matter how some sports are challenging |
Although __________ to be the best in a recent science competition, the students remain hard-working.
| A．judged | B．judging |
| C．judge | D．having judged |
-You aren't looking well. Anything the matter?
-I've been surfing the net too long. I'm a bit tired. I can hold on，__________.
| A．though | B．yet |
| C．besides | D．therefore |
__________ life is full of ups and downs, where there is life, there's hope.
| A．When | B．Although |
| C．Since | D．Unless |