A life preserver or buoyant work vest is required to be worn on a ship when a person is （）.

单项选择题A latitude line will be obtained by observing a body （）.

A.on the prime vertical
B.on the celestial horizon
C.at lower transit
D.on the Greenwich meridian

单项选择题A lashing used to secure two barges side by side，lashed in an X fashion，is called a （）.

A.quarter line
B.back line
C.peg line
D.jockey line

单项选择题A lashing used to secure two barges side by side，lashed in an X fashion，is called a （）.

A.scissor wire
B.towing wire
C.breast wire
D.cross wire

单项选择题Information on the operating times and characteristics of foreign radiobeacons can be found in which publication? （）.

A.List of Lights
B.Coast Pilot
C.Sailing Directions
D.List of Radiobeacons

单项选择题The Mariner’s Handbook （）general information affecting navigation and is complementary to the Sailing Directions．

A.giving
B.give
C.gives
D.given