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.
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.
Achores; by 1997 they had spent nearly six hours a week 分析A选项
Bchores; by 1997 that figure had grown to nearly six hours a week 分析B选项
Cchores, whereas nearly six hours a week were spent in 1997 分析C选项
Dchores, compared with a figure of nearly six hours a week in 1997 分析D选项
Echores, that figure growing to nearly six hours a week in 1997 分析E选项