A.ClearB.EvidentC.ObviousD.ApparentlyAll the traces are……

单项选择题A VESSEL，OTHER THAN A RESCUE UNIT，DESIGNATED TO CO-ORDINATE SURFACE SEARCH AND RESCUE OPERATION WITHIN A SPECIFIED AREA is known as（）.

A.Salving vessel
B.Co-ordinator surface search
C.MERSAR
D.The vessel being salved

单项选择题（）is not a search pattern.

A.Williamson Turn
B.Parallel
C.Sector
D.zig-zag maneuver

单项选择题（） is not a search manual.

A.MERSAR
B.IMOSAR
C.ICAO SAR
D.SOSREP

单项选择题（）is a an aircraft used in SAR.

A.MRCC
B.SOSREP
C.MCA
D.3A

单项选择题Which statement about firefighting foam is TRUE?（）

A.Foam conducts electricity
B.To be most effective，foam should be directed at the base of the fire
C.Foam is most effective on burning liquids which are flowing
D.Foam can ONLY be used to extinguish class A fires