“I don’t like to travel
” “ Have you ever _____ in an airplane
flying b
flew c
flowed d
flown 2
The center of gravity of the human body ______ behind his joint
located b
locating c
to locate d
is located 3
“Today is very cold, isn’t it
” “ Yes, the river is _____ over
freezed b
freeze c
frozen d
freezing 4
“What happened in that new area
” “ New houses ______ recently over there
are built b
build c
have built d
have been built 5
“When did you go to work
” “ As soon as they came, we ______ to work
went b
were going c
had gone d
“Did you wait for him very long
” “ Yes, I ______ to bed until five in the morning
did go b
didn’t go c
had gone d
went 7
Perhaps it will be a long time ______ from abroad
when Tom comes back b
when Tom will