Section16:6. Until the current warming trend exceeds the range of normal climatic fluctuations, there will be, among scientists, considerable___the possibility that increasing levels of atmospheric CO2 can cause long-term warming effects.
(A) interest in
(B) uncertainty about
(C) enthusiasm for
(D) worry about
(E) experimentation on
看解析说Until表示before的意思,然后过去和现在情况相反,现在是warming trend exceeds the range of normal climatic fluctuations,所以过去是不确定是否为温室效应,所以选了B。但是主句那里不是there will be吗?也就是应该是将来的情况啊,现在是温室效应,将来科学家应该会更确定了才对啊。如果是主句表示过去的话不应该是there would be吗??这道题费解了……:dizzy: