Ollier病属于（）.
A.骨组织肿瘤
B.软骨组织肿瘤
C.纤维组织肿瘤
D.骨髓组织肿瘤
E.滑膜组织肿瘤
参考答案：B
--- He has never learned French．
---- __________．
A．So I did
B．So have I
C．Nor I have
D．The same with me．
井深H=1000m，气侵前钻井液密度1.20g/cm3，气侵后返至井口的钻井液密度0.60g/cm3，Ps=0.0981MPa，井底钻井液柱压力减少值（）。
A.0.47MPa
B.0.87MPaMPa
C.0.97MPa
D.1.40MPa
