Compared to internal structural plating，the exterior hull plating on a ship is usually（）.

单项选择题Compared to a low pressure system，generally the air in a high is（）.

A.warmer，less dense，and less stable
B.cool，more dense，and drier
C.muggy and cloudy
D.extremely moist with high relative humidity

单项选择题Commercial ships or other persons or agencies requiring the assistance of Canadian Coast Guard icebreakers should first contact（）.

A.the Canadian Coast Guard
B.Ice Sarnia
C.the Ice Navigation Center
D.the icebreaker assigned to the area

单项选择题Coiling new rope against the lay，bringing the lower end up through the center of the coil，then coiling with the lay，in order to remove the kinks，is known as（）.

A.coiling
B.faking
C.flemishing
D.thoroughfooting

单项选择题Coast Pilots and navigational charts are kept corrected and up-to-date by using the（）.

A.pilot charts
B.Notices to Mariners
C.Tide Tables
D.Current Tables

单项选择题Clouds with the prefix “nimbo” in their name（）.

A.are sheet or layer clouds
B.have undergone great vertical development
C.are middle or high altitude clouds
D.are rain clouds