2000-10-39

39．While photosynthesis in green plants, light energy is captured and used to convert  water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds.

不明白为什么是A, 哪位帮忙解释一下.

D的minerals不应该有s吧?

while->during

while 是连词 ，不能跟名词。

minerals 是可数的，toelf里的 mineral 基本都可数，当然也有不可数的情况，你 look look your dictionary!