宾语从句I don't know _ to visit the old man.A whether B if
问题描述:
宾语从句
I don't know _ to visit the old man.A whether B if
答
A疑问代词whom、what、which、连接词whether(不能用if)、疑问副词when、where、how常常与动词不定式连用,构成一种特殊的动词不定式短语,可以作主语、直接宾语、表语、介系词的宾语等.如:How to fight pollution i...