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

问题补充：

the Internet is of great help, I don’t think it’s a food idea to spend too much time on it.

A. If

B. While

C. Because

D. As

答案：

A. If

(答案→)B. While

C. Because

D. As

解析：考查连词：A. If如果，B. While虽然，C. Because因为D. As由于，正如，句意;虽然因特网很有用，但我认为花太多时间在上面不是好主意。选B。