【简答题】经营活动产生的现金流量大于零说明企业盈利。( )
【判断题】在生物体内环境中,电子受体不一定是氧,只要它具有比电子供体较正的E0时呼吸作用就能进行。
【单选题】Which of the following is a characteristic of a natural monopoly?
A.
Marginal cost declines over large regions of output.
B.
Average total cost declines over large regions of output.
C.
The product sold is a natural resource such as diamonds or water.
D.
All of the above are correct.
【判断题】在生物体内环境中,电子受体不一定是氧,只要它具有相比电子供体的正E0时,呼吸作用就能进行。
【单选题】a natural monopoly exists because:
A.
the government is the only supplier
B.
economic and technical conditions permit only one efficient supplier
C.
other firms are unable to enter the industy
D.
the firm owns natural resources