What form of ice is of land origin?()
A.Shuga
B.Floe
C.Spicule
D.Bergy bit
参考答案:D
某工程测得中等风化岩体压缩波波速Vpm=3185m/s,剪切波波速Vs=1603m/s,相应岩块的压缩波波速Vpr=5067m/s,剪切波波速Vs=2438m/s;岩石质量密度ρ=2.64g/cm3,饱和单轴抗压强度Rc=40MPa。则该岩体基本质量指标BQ为下列何项数值()
A.255
B.310
C.491
D.714
支撑线只有在下跌行情中才存在,压力线只有在上升行情中存在。______