The dew point is reached when the（）.

单项选择题The design specifications for cranes and crane foundations on ship’s are set and published by the（）.

A.American Society of Mechanical Engineers
B.American Petroleum Institute
C.Society of Petroleum Engineers
D.American Society of Civil Engineers

单项选择题The depth（）a shallow patch，lying about 1.3 miles southeastward of Nanshan Tou lighthouse reduces to about 6.1 meters.

A.above
B.over
C.up
D.upon

单项选择题The datum from which the predicted heights of tides are reckoned in the tide tables is（）.

A.mean low water
B.the same as that used for the charts of the locality
C.the highest possible level
D.given in table three of the tide tables

单项选择题The dangerous semicircle of a typhoon in the Southern Hemisphere is that area（）.

A.measured from due south clockwise 180°
B.measured from due south counterclockwise 180°
C.to the left of the storm's track
D.ahead of the typhoon measured from the storm's track to 90°on each side

单项选择题The dangerous semicircle of a hurricane in the Northern Hemisphere is that area of the storm （）.

A.to the right of the storm's track
B.measured from true north clockwise to 180°T
C.measured from true north counterclockwise to 180°T
D.between the ship's heading and the bearing to the eye