All the traces are（）old ones.A.clearB.evident

A man was sighted as he fell overboard. After completin...

单项选择题A man was sighted as he fell overboard. After completing a Williamson turn，the man is not sighted. What type of search should be conducted?（）

A.Expanding circle
B.Sector search
C.Parallel track pattern
D.Datum-drift search

（）the visibility to reduce to one mile by heavy rain，it...

单项选择题（）the visibility to reduce to one mile by heavy rain，it（）be impossible to rescue the vessel in distress.

A.Was／would
B.Were／would
C.Is／will
D.Is／is to

If more than one raft is manned after the vessel has su...

单项选择题If more than one raft is manned after the vessel has sunk，you should（）.

A.go in a different direction in search of land
B.spread out to increase the possibility of a search aircraft finding you
C.reduce the number of rafts by getting as many people as possible into as few rafts as possible
D.tie the rafts together and try to stay in a single group

搜索用语

All the traces are（）old ones.