第一句：They usually do their difficult homework first，and then do easy ones at last.第二句：They review their lessons usually at night，such as maths and politics. 若不能加多余的单词：第一句：They usually do dolls easily.他们做玩偶通常很容易。第二句：They reviewed up maths，politics. 他们审查(回顾)了数学，政治。
小M回归中
