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
–We’ve decided _______ on a trip this afternoon. Will you join us? -- I’m afraid not. I have some problems ___________ out.
#48703
A
to go, to work
B
to go , working
C
going. to work
D
doing, working
—It’s necessary ____ our environment(环境). —I agree with you.
#50553
A
protect（保护）
B
protecting
C
to protect
D
protects