T-4-Q12

For the farmer who takes care to keep them cool, providing them with high-energy feed, and milking them regularly, Holstein cows are producing an average of 2,275 gallons of milk each per year.

A.    providing them with high-energy feed, and milking them regularly, Holstein cows are producing

B.    providing them with high-energy feed, and milked regularly, the Holstein cow produces

C.    provided with high-energy feed, and milking them regularly, Holstein cows are producing

D.    provided with high-energy feed, and milked regularly, the Holstein cow produces

E.     provided with high-energy feed, and milked regularly, Holstein cows will produce

答案：E。请教下D和E两个选项的区别是什么呢？为什么选E而不是D呢？是不是E选项中有each导致前面的cows要用复数呢？我对这个语法点一点都不了解。。。。或者，D和E有什么其他的解题点呢？

For the farmer who takes care to keep them cool, providing them with high-energy feed, and milking them regularly, Holstein cows are producing an average of 2,275 gallons of milk each per year.

因为那个them指代的是cows，所以必须是复数的名词来对应，单数不可以

因为那个them指代的是cows，所以必须是复数的名词来对应，单数不可以