It is quite necessary for a qualified teacher to have good manners and ______ (extension)

学历类 成人英语三级 已帮助 人

It is quite necessary for a qualified teacher to have good manners and ______ (extension) knowledge.

请帮忙给出正确答案和分析,谢谢!

热搜:for语句中的表达式可以部分或全部省略