题目内容：

The price of diamond rings has risen____the price of gold rings has gone down(求解释）
A when B as C while D otherwise

优质解答

C
while 在这里是并列连词,表对比 “而” “然而”
再如：
This room is very clean,while that one is very dirty.
这个房间很干净,可那个房间却很脏