it is not alwasy easy for the public to see what use a New invention can be of to human life宾语为什么不选which
问题描述：
it is not alwasy easy for the public to see what use a New invention can be of to human life
宾语为什么不选which
答
what好像是做宾补吧
答
what引导宾语从句what 做see 的宾语
which有意思哪一个,放在这里不通