the Internet is of great help I don't think it's a good idea to spend too much time on i

问题补充：

the Internet is of great help, I don think its a good idea to spend too much time on it.

A If B While C Because D As

答案：

解析：考查连词用法。A如果；B当…时；尽管；C因为；D因为，当…时；句意：尽管因特网对我们很有益处，但是我认为把太多的时间花在上面并不是一个好主意。本题的while意为：尽管。故B正确。