Three years had gone by ____ he came to realize what a fool he was not to listen to the teachers !
| A．until | B．since | C． before | D．after |
Exercise is ________ as any other to lose unwanted weight.
| A．so useful a way | B．as a useful way | C．as useful a way | D．such a useful way |
The Haiti earthquake at the beginning of 2010 is believed _______ more than 100,0130 people and makes millions homeless, ______ it perhaps the most destroying earthquake in history.
| A．to kill; making | B．to have killed; making | C．having killed; to make | D．killing; made |
Canada's economic wealth is closely linked to _______ of the US, which buys three-quarters of its exports.
| A．which | B．what | C．that | D．one |
Thanks to your help, ________ I would not have completed the task on time.
| A．however | B．because | C．so | D．otherwise |
The conflict had developed into a stage ______ the two countries were gathering big troops on the border.
| A．where | B．when | C．which | D．that |