99色精品-9色在线-99色在线-99色视频 国产欧美日产一区二区三区_亚洲精品亚洲人成在线观看_四虎在线精品永久观看_免费一级a一片久久精

單項(xiàng)選擇題

Guide tolerances during elevation of the jack-up rig will().

A.reduce spud can bearing pressure
B.keep the unit level and reduce overloading
C.reduce stresses on the hull
D.minimize the potential for punch-through

微信掃碼免費(fèi)搜題