水的质量流量为20t/h,温度为90℃,则体积流量为()m/h.(90℃时水的密度为965.3Kg/m3).
A.20
B.20.72
C.21.96
D.19.84
参考答案:B
Two mooring lines may be placed on the same bollard and either one cast off first if().
A.the eye of the second line is dipped
B.the mooring lines are doubled
C.the bollard has two horns
D.one of the lines is a breast line