【多选题】根据聚合物主链所含元素,又可将聚合物分为( )。
【单选题】在下面选项中,哪一项不能起到减少着陆滑跑距离的作用?
【单选题】While income worry is _______ rather common problem of the aged, loneliness is another problem that _______ aged parents may face.
【单选题】While income worry is ____ rather common problem of the aged,loneliness is another problem that ____aged parents may face.
【简答题】命名下列聚合物,并根据其主链结构指出它们属于碳链聚合物、杂链聚合物、还是元素有机聚合物?
【单选题】She was thinking over the problem again on her way home, when she found herself _______ in front of his company.
【简答题】试指出下列结构的聚合物,其溶解过程各有何特征?(1)非晶态聚合物;(2)非极性晶态聚合物;(3)极性晶态聚合物;(4)低交联度的聚合物。