若|ab|=ab，则 [ ]
A．a<0，b<0
B．ab>0
C．ab≥0
D．a，b同号
答案：C
The doctor’s treatment has worked marvels: the patient has completely．
A．repeated
B．returned
C．recovered
D．reminded
物流客户服务水平对企业经营绩效有直接影响
