89. The task is hard, ____, the workers managed to finish it in time.
| A．therefore | B．otherwise | C．however | D．Yet |
The production of the factory has grown to _____ in 1999.
| A．twice as it was | B．twice what it was |
| C．as twice as it was | D．twice that it was |
What troubled the teacher was that no one present made an answer when asked who had broken the glasses, so he didn’t know who _____________.
| A．was blamed | B．was to be blamed | C．was to blame | D．would be blamed |
____ the Internet is of great help, I don’t think it’s a good idea to spend too much time on it.
| A．If | B．As | C．Because | D．While |
I told her we weren’t going to be friends any more because she couldn’t ________ .
| A．keep her word | B．have her word | C．keep her words | D．have her words |
Research has been limited to ____ production profits, rather than ____ that GM foods are safe.
| A．increasing; make sure | B．increasing; making sure |
| C．increase; make sure | D．increase; making sure |