一道柔和了各种时态的题￣￣

天正

15.   People have discovered the principles of solar energy whenever fuel becomes scarce and expensive but will forget them every time a new source of cheap energy is developed.

(A) have discovered the principles of solar energy whenever fuel becomes scarce and expensive but will forget

(B) have discovered the principles of solar energy whenever fuel has become scarce and expensive but they forget

(C) discovered the principles of solar energy every time fuel becomes scarce and expensive, forgetting

(D) discover the principles of solar energy every time fuel became scarce and expensive, but they forget（E）

(E) discover the principles of solar energy whenever fuel becomes scarce and expensive but forget

如何选择？？

苏小慕

绝对新手，昨天开始准备材料，蒙一下，是不是D

天正

大全上的答案是E　?我也不有疑问

gyan

从答案入手，
            经蒙得：

 

A, B - Whenever 表发生频率，
            主句不能用完成时

C – every time 应该用一般现在时，而不是过去时

D – but 做连词，
            连接两个句子，第二个句子they and them只待不清

E – best, but 做连词，
            连接同一个主语发出的动作，
            people discover …. But forget ….时态正确，平行结构完整

dongbird

答案应该是e, 我觉得这是一道考并行结构的题。大概意思是当fuel 贵的时候，人们总能发现太阳能的一些东东，但是当有便宜的能源被发现的时候，人们就会忽略的太阳能的blah blah.我理解的大概就是这些，不是台擅长英汉互译
1) discovere 和 forget应该是一样时态。
2）they 是discovere 和 forget 得主语，第二个动词forget,省略主语

clairetong

从最后一部分“every time a new source of cheap energy is developed”知道整个句子在一般时环境下的。

选E

天正

像whenever 和every time 这样的词是不是就有暗示其引导的句子就应该用一般时呢　

gyan

我理解是， 但是没时间查证据和出处。

天正

这题就是主从句的时态比较复杂　

db5288

个人理解：
客观事实+平行，选E