If we _________ now to protect the environment, we’ll live to regret it. 
#100580
A
hadn’t acted
B
haven’t acted
C
don’t act
D
won’t act
推荐题目
---Ring me at six tomorrow morning, will you ?---Why that early ? I _____then.
#101802
A
have slept
B
have been sleeping
C
will sleep
D
will be sleeping
Ladies and gentlemen, please fasten your seat belts .The plane _____ .
#101606
A
takes off
B
is taking off
C
has taken off
D
took off