It _____ everyone to hear all of the villagers behind the mountain were killed in the flood. [ ]

A. suffered            

B. shocked      

C. persuaded          

D. destroyed

有关二甲苯塔底泵冷却水作用不正确的描述是（）。

A.防止轴承抱轴

B.防止机械密封失效或者损坏

C.防止机械密封摩擦面泄漏出来的有害气体污染环境

D.防止离心泵内液体的温度升高产生汽蚀