生产成本-基本生产成本-直接福利费
参考答案：
指的是按参加产品生产员工的福利费。
在同一平面内，已知三条直线两两相交最多有a个交点，最少有b个交点，则a+b的值为（ ）
A．1
B．2
C．3
D．4
_________that developed countries want to limit the development of the developing countries in the climate conference in Copenhagen.
A．It is no possibility
B．It is small wonder
C．There is no denying
D．There is no chance
