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

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

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（）.