It is necessary _____ something to protect our environment.
#50188
A
do
B
to do
C
does
D
doing
推荐题目
What would you like ______, tea or coffee?
#50691
A
have
B
drink
C
to drink
D
to eat
-Last semester, he had a hard time______ English.
#50462
A
learns
B
learning
C
to learn
D
learnt
We prefer ________at the party to________. 
#49934
A
to sing, dance
B
singing ,dancing
C
to sing , dancing
D
sing, dance
Thank you for ______ me go on the trip ,Mr Wu.
#50113
A
agreeing letting
B
agree to let
C
agree letting
D
agreeing to let