J____p v. 跳
A. um
B. un
C. am
D. an
We're ____ books in the classroom.
A. looking
B. reading
C. seeing
D. looking at
Mr. Jones, with his family, ____ over the bridge.
A. walking
B. is walking
C. are walking
D. aren't walking
What about ____ our homework?
A. do
B. doing
C. to do
D. does