2016年托福写作常见错误：家务对儿童的好处

　　找出下列句子的一处 语法错误：
　　According to a study, conducted over a period of twenty years, Prof. Rossman from the University of Minnesota pointed out that children who undertake household chores at ages three to four as less inclined to use drugs and are more likely to maintain a better relationship with his/her family.
　　♜ 适用考题：
　　Children should spend most of their time studying and playing; they shouldn’t be required to help the family with household chores, such as cleaning and washing. (2011.3.13)
　　答案：暂无