He seldom does his homework at school on weekdays,()he?
A.doesn‘t
B.isn‘t
C.does
D.is
参考答案:C
工程上常用的APP防水卷材,属于()。
A.高分子卷材
B.玻璃布胎沥青油毡
C.弹性体改性沥青防水卷材
D.塑性体改性沥青防水卷材