金老师您好，这道题我曾经在AB选项中纠结，最后还是选了C。虽然说分号后面接完整句子能够更完整表达句意，而且年份放在前面很清楚，但是B选项中had grown用了过去完成时代表过去的过去，1981年用了过去式，1997年为什么反而要用过去的过去呢？相反我觉得C选项有个转折对比关系更清楚。

觉得C也没有犯错，而且比B要简洁

我的思路： 看到had grown， 并且题目中没有明确暗示时间点，于是排除A，B C被动表达意思不明确排除， 没有疑问， 最后剩下D和E感觉都没错， 瞎蒙了D 请问， D和E为什么不行？

b c

我选择的是C，但是答案是B ，这里面要如何判断呢？ 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 sixhours a week.） chores; by 1997 they had spent nearly six hours a week chores; by 1997 that figure had grown to nearly six hours a week chores, whereas nearly six hours a week were spent in 1997 chores, compared with a figure of nearly six hours a week in 1997 chores, that figure growing to nearly six hours a week in 1997

老师不是说要对动词有足够敏感吗？而在B选项中的had grown是过去完成时，表达过去的过去。而在OG中有提到，用过去完成时需要有明显的时间先后顺序。因此，当时我认为虽然B从结构上更加对称，但是从意思上说，had grown却变成了在spent之前了，这从意思上说就不对了，因此就排除了B。所以想请问一下管老师，按照新方法来说，究竟应该分析动词的时态吗?