After graduating from college，I took some time off to go travelling，________ turned out to be a wise decision.(2010·四川，10)
| A．that | B．which | C．when | D．where |
It is in their ability to speak ______ humans ______ from animals.
| A．which; differ | B．that; different | C．which; different | D．that; differ |
Tom, look at your shirt! It requires ________.
| A．washing | B．washed | C．to wash | D．being washed |
I am concerned ____ it that I can’t concentrate ____ my work because of headache.
| A．of; on | B．of; of | C．about; on | D．about; to |
_____of danger in the street at night, she had to go home, with a friend_____ her.
| A．Warned; accompanied | B．Warning; accompanying |
| C．Having warned; accompanied | D．Having been warned; accompanying |
—Jack is very clever and he studies hard as well.
—It’s no ______ he always comes out first in the exams.
| A．doubt | B．need | C．wonder | D．problem |