In order to _____ the rising production costs, the subscription rates have been increased.
| A．add up to | B．look up to | C．cut short | D．keep up with |
---I’ll be away in a few days. Would you mind looking after my dog?
---Not at all. _________
| A．I can’t spare time | B．I’d rather not | C．You can do it | D．I’d be happy to |
His eyes suddenly widened. I knew a good idea must have _________ to him.
| A．happened | B．appeared | C．occurred | D．hit |
The World War II made_________ impossible for Einstein to go on with his research.
| A．him | B．it | C．this | D．that |
We had _________ great fun at the charity party yesterday. I have never had _________ more exciting experience.
| A．a, / | B．/, a | C．/, the | D．the, a |
The scientists were trying to look for all possible _______ as to where this species came from.
| A．signals | B．marks | C．clues | D．spots |