A、  B、  C、  B问句里加上don’t you think的成分，要求对方对说话内容表示肯定。问句说使用新的网络系统容易多了，(B)回答说确实是个很大的进步，同意了问句的意见，因此是正确答案。

Do you live down by the river?
(A) The ferry terminal is on the river.
(B) The river runs north to south.
(C) Yes, that’s where I reside.

This new network system is much easier to use, don’t you think?
(A) I think it’s a new system.
(B) Yes, it’s quite an improvement.
(C) It’s a brand-new computer.