The Internet is a very useful invention for us, we can do lots of things at home.
A. with which
B. with it
C. for which
D. for it
网友回答
(答案→)A. with which
B. with it
C. for which
D. for it
解析：考察定语从句。本题定语从句的先行词是a very useful invention,后面的定语从句很完整，故使用关系副词，本题中的关系副词=介词+which,本题中的介词with表示“用”。句意：网络一个很游泳的发明，使用网络我们可以在家里做很多的事情。故A正确。