18. Deng Xiaoping was our general designer of reform and opening up to the outside world(改革开放). After he passed away, his ____were scattered over the sea.

A．ashes

B．ash

C．dusts

D．Dust

下面那一项不是双转子流量计复合壳体所具有的特点（）。

A、计量精度不受液压变化及安装条件的影响

B、不受环境温度的影响

C、在管道上可以直接维修

D、噪声小，无脉动