题目

Peter always helps his mother housework.A. do B. doing C. with doing D. with do 答案：【答案】A【解析】句意：彼得总是帮助他的妈妈做家务。do做，动词原形；doing动名词；with doing介词+动名词。help somebody do something帮助某人做某事；help somebody with something在某方面帮助某人。根据句意及结构，故选A。17．1.2÷x=0.4的解是（　　）A．3B．0.48C．3.6