In order to get the exact result, the scientists made _______.
| A．a lot tries | B．to do experiments | C．trial and error | D．great try |
Although new problems ______ during the last experiment, they didn’t give up.
| A．came | B．raised | C．arose | D．rose |
Some people always take seriously the ______ of the complete globe end in the near future.
| A．celebration | B．production | C．prediction | D．permission |
— Did you visit the museum today?
— No. We ______ it, but we spent too much time shopping.
| A．could have visited | B．must have visited |
| C．may have visited | D．couldn’t have visited |
I am going to do ______ I can ______ him a good impression.
| A．all what, leave | B．all, to leave | C．all that, leave | D．what, leave |
Some of the doctors are paid almost ______ as the nurses.
| A．twice as much | B．much as twice | C．as much twice | D．as twice much |