单项选择题 A set of clamps that are latched onto the drill pipe to allow the driller to raise or lower the drill string out of or into the hole are the（）.

单项选择题 A series of trays with sieves that vibrate to remove cuttings from the circulating fluid in rotary drilling operations is called the（）.

单项选择题 A semisubmersible with a positive GM，and TCG located starboard of the centerline，inclines to an angle of（）.