单项选择题
A.yearly inspection B.quarterly inspection C.monthly inspection D.weekly inspection
A sheepshank is used to（）.A.keep a line from frayingB.j...
单项选择题A sheepshank is used to（）.
A.keep a line from fraying B.join lines of unequal size C.stop off a line D.shorten a line
A sextant having an index error that is off the arc has...
单项选择题A sextant having an index error that is off the arc has a（）.
A.positive correction B.dip error C.negative correction D.semidiameter error
A DECK，SPACE，AREA，ETC.，NOT PERMITTED TO BE ENTERED FOR ...
单项选择题A DECK，SPACE，AREA，ETC.，NOT PERMITTED TO BE ENTERED FOR SAFETY REASONS defines（）.
A.Restricted area B.Closed area C.Prohibited place D.Forbidden place
