A business firm reduces the number of hours its employees work from 40 hours per week to 36 hours per week while continuing to pay the same amount of money. If an employee earned x dollars per hour before the reduction in hours, how much does he earn per hour under the new system ？（）

A.A

B.B

C.C

D.D

E.E

将污染影响程度和植被或动物分布叠置成污染物对生物的影响分布图，此种生态现状评价方法为( )。

A．生态机理分析法
B．图形叠置法
C．质量指标法
D．生产力评价法