An oiler was badly burned and you are communicating with a passenger ship that has a doctor and hospital on board. You want to rendezvous in a certain position so the oiler can be evacuated for medical treatment. Which code should your message contain?（）

A.a line on a weather map connecting equal points of both temperature and pressure
B.an instrument that measures the climatological effects of temperature
C.a line connecting points of equal barometric pressure on a weather map
D.a line connecting points of equal temperature on a weather map

A.fitted in each leg of the towing bridle
B.generally located between the "fishplate" and the main towing hawser
C.secured at the "H" bitts
D.usually made of manila hawser

A.thermometer
B.barometer
C.hygrograph
D.thermograph