B is right. 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 [they refer to the children is 1981, wrong meaning] 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 [(1) passive; (2) in 1997, total 6 hours a week were spent on what - the meaning is not clear. ] D. chores, compared with a figure of nearly six hours a week in 1997 [children is the subject of "compared with figure...", wrong meaning] E. chores, that figure growing to nearly six hours a week in 1997 [In 1981 children spent..., that figure growing to... in 1977 - How an action is 1977 accompanied with another action in 1981? Not logical.]
Therefore, though B is the right answer, though it is not perfect due to its past perfect tense.
[此贴子已经被作者于2007-9-8 21:04:00编辑过] |