求助GWD26-Q20

GWD26-Q20

In 1981 children in the United States spent an average
        of slightly less than two and a half hours a week doing
        household chores; by 1997 they had spent nearly six hours a week.

A.      chores; by 1997 they had spent nearly six hours
        a week

B.       chores; by 1997 that figure had grown to nearly
        six hours a week

C.      chores, whereas nearly six hours a week were
        spent in 1997

D.      chores, compared with a figure of nearly six hours a week in 1997

E.       chores, that figure growing to nearly six hours a week in 1997

选B，不是很明白。我选的C

A：they精确指代children,错误

D：compared逻辑主语不一致

E：growing做伴随改变了句意

有人说C错是因为in 1997改变了句意，但是我觉得句子本身要表达的意思就是1981年和1997年情况的对比。请大家指正，谢谢。

前后句应该是并列关系 肯定用分号，此外A选项误用了TYEY， 所以选B

C选项在可以选择的情况下用了被动，是不建议的！

我觉得前句的重点在figure的大小上，选B前后重心一致

我们用中文念叨几句就会感觉更深一点

B：1981年美国小孩每周平均花小两个半小时做家务，到了97年这个数字升至6小时

C：1981年美国小孩每周平均花小两个半小时做家务，到97年6小时被花在这上面

读几遍会发现B更连贯,而且C的被动没必要

搞不太清楚为什么(A)不对，分词前面主语是children, 分词后面用they，感觉很对称啊?? 请指教....谢谢!!