a phone is of great help I don’t think it’s a good idea to spend too much time on it.A.

问题补充：

a phone is of great help, I don’t think it’s a good 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：考查连词辨析。A如果；B当…时；然而；尽管；C因为；D因为，随着；句意：尽管电话对人也许很有帮助，第我认为在电话上花太多的时间这不是一个很好的主意。故B正确。本题的while表示尽管。