钢丝绳损坏报废标准主要有（）严重打结等现象。
A.断丝数达总丝数2%
B.绳径变小
C.笼形畸变
D.断股
参考答案：B, C, D
正常的横扫球击球时，位于板柄（）手发力，紧握球板。
In the piping systems of a vessel，what type of valve gives the least resistance to fluid flow when fully open?（）.
A.Globe valve
B.Butterfly valve
C.Gate valve
D.Packless valve
