人民警察离休,退休的,其警衔予以(),但不得佩带标志。
A、保留
B、收回
C、没收
D、取消
参考答案:A
设y=f(x)是由方程组所确定,求f’(x)。
Expo 2010 Shanghai China __________ on both banks of the Huangpu River in the city of Shanghai, China, from May 1 to October 31, 2010.
A.is being held
B.is holding
C.will hold
D.holds