SAT语法逻辑及平行结构问题To meet the rapidly rising market demand for fish and seafood,suppliers are growing fish twice as fast as their natural growth rate,cutting their feed allotment by nearly half and raising them on special diets.(A)

SAT语法逻辑及平行结构问题To meet the rapidly rising market demand for fish and seafood,suppliers are growing fish twice as fast as their natural growth rate,cutting their feed allotment by nearly half and raising them on special diets.(A)
SAT语法逻辑及平行结构问题
To meet the rapidly rising market demand for fish and seafood,suppliers are growing fish twice as fast as their natural growth rate,cutting their feed allotment by nearly half and raising them on special diets.
(A) their natural growth rate,cutting their feed allotment
(B) their natural growth rate,their feed allotment cut
(C) growing them naturally,cutting their feed allotment
(●) they grow naturally,cutting their feed allotment
(E) they grow naturally,with their feed allotment cut
我觉得选D不妥在于,与比较结构的前半句 suppliers are growing fish twice 的主语不同,主语由suppliers变成了they.我觉得they在这里指代不明,既然出现了两个复数名词.而C并没有改变主语.

SAT语法逻辑及平行结构问题To meet the rapidly rising market demand for fish and seafood,suppliers are growing fish twice as fast as their natural growth rate,cutting their feed allotment by nearly half and raising them on special diets.(A)
选D是对的.这里涉及到 as...as...句型的用法.这两个as的词性,有两种可能：第一种是第一个as 是副词,第二个 as 是介词.例如 He runs as fast as a bird.(他跑得像鸟一样快.)第二种可能是第一个 as 仍是副词,但第二个 as 是连词,连接一个状语从句.例如 He can spend as much money as he wishes.(他想花多少钱就能花多少钱.) 因此,在原句中,twice as fast as their natural growth rate 里的第二个 as 是介词,而在替换选项 D 中,twice as fast as they grow naturally 的第二个 as 是连词,连接一个状语从句,而句子的意思并没改变.they 是指fish,注意这个 fish 是复数形式.如果在they之前有两个复数名词的话,一般指代离they最近的那个名词,不会模棱两可的.
选C有什么不好呢?我们尝试一下：suppliers are growing fish twice as fast as growing them naturally,cutting their feed allotment by nearly half and raising them on special diets.这样一来,cutting...and raising...这两个现在分词,究竟是与第一个 growing 构成平行结构,还是与第二个 growing 构成平行结构?这就模棱两可了,就不是一个好句子.而使用选项D,三个现在分词 growing...cutting...and raising...构成的平行结构,很清楚.所以D比C更好.