_____ the environment is important for human beings.
A.Take care of B.Taking care of C.Took care of D.Take the care of
He wants to be a doctor ________ his parents want him to _______ the army.
A.while, join B.when; join C.while; join in D.when; join in
—David has made great progress recently. — , and .
A. So he has; so you have B. So he has; so have you
C. So has he; so have you D. So has he; so you have
Now most families have only one child _____ our country’s one-child policy.
A.so B.because C.because for D.because of
—How long have you been in Beijing？
—_____
A.Five years ago. B.Since five years ago.
C.For five years ago. D.Since five years.
There are five people in the room, but I know _____.
A. both of them B. none of them
C. all of them D. neither of them
