We must do everything we can _________ our earth clearer and safer.
#49701
A
made
B
to making
C
make
D
to make
推荐题目
My parents asked me ______ my sister with her schoolwork.
#49376
A
help
B
to help
C
helping
D
helped
—It’s necessary ____ our environment(环境).  —I agree with you. 
#50553
A
protect(保护)
B
protecting
C
to protect
D
protects
She finished _____ that book last Sunday.
#51115
A
reading
B
to read
C
reads
D
read
It’s hot inside. You’d better         the room.
#50398
A
get out
B
to get out
C
get out of
D
to get out of