885-21-15求解~~~指代问题

一加heidy

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) discover the principles of solar energy whenever fuel becomes scarce and expensive but forget
答案选E，我选了D，因为看到没画线的部分有every time，觉得画线的也这么用对称呢~D中的they是否是可以既指代人又指代物呢？感觉指代不清呢

laurie641000

个人感觉是D项的 became有误，违反整句时态

lijiazhou

they 是指代不清楚的，因为they 后面的them指代的不是people，所以导致混乱

一加heidy

那不能they指人，them指物么？说不能同一代词指代不同的东西，可是they them是两个代词呢

一加heidy

是哦~~现在发现了，谢啦~~