In order to keep the balance of ecosystem, every possible means _______to deal with the problems of the over-exploiting of natural resources.
#101293
A
has tried
B
has been tried
C
have taken
D
have been taken
推荐题目
The town’s drinking-water _____ with prim chemicals at present.
#104183
A
contaminates
B
is contaminated
C
is being contaminated
D
has been contaminated
Tom, together with his classmates, ______ because of _______ the school rules.
#103624
A
was punished, obeying
B
were punished, obeying
C
was punished, breaking
D
were punished, breaking
I ＿＿ ping-pong quite well, but I haven’t had time to play since the new year.
#104422
A
will play
B
have played
C
played
D
play
—Car prices have been going down sharply in the last 20 years.—It's not surprising because the law of market ________ the price of a product.
#99495
A
is controlling
B
controls
C
has controlled
D
controlled
Mr. Black ________ for Shanghai in a few days. Do you know when the earliest plane ________ on Sunday?
#100397
A
leaves; takes off
B
leaves; is taking off
C
is leaving; is taking off
D
is leaving; takes off