As we all know,________, the pollution will get worse and worse.
A.not if carefully dealt with |
B.until not carefully dealt with |
C.if not carefully dealt with |
D.when not carefully dealt with |
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As we all know,________, the pollution will get worse and worse.
A.not if carefully dealt with |
B.until not carefully dealt with |
C.if not carefully dealt with |
D.when not carefully dealt with |