在市场经济体制下，城市建设的开展在相当程度上需要依靠市场机制的运行，但单纯的市场机制运行会出现（）的现象。

A."市场停滞"

B."市场失效"

C."市场缩小"

D."市场扩大"

I am trying to do what is best, but ______ I’ve got to consider the cost, which is of great importance.

A．equally

B．eventually

C．naturally

D．evidently