One learns a language by making mistakes and ______ them.
| A．corrects | B．correct | C．to correct | D．correcting |
We should take some measures to______ wild animals______.
| A．protect ; from being killed | B．prevent; from killing |
| C．keep; being killed | D．stop; from killing |
There is just _______ much competition among countries to host the Olympics as ______ Olympic medals.
| A．as ; to win | B．as; winning | C．so; to win | D．so; winning |
When we talk about the cities in United States, the first ________comes into our mind is New York.
| A．one | B．city | C．that | D．which |
Gun control is a subject ________Americans have argued for a long time.
| A．of which | B．about which |
| C．with which | D．into which |
Mary _________a professor for half a year.
| A．has married | B．married with |
| C．married | D．has been married to |