单项选择题
Downwind for 1 miles，alter to starboard 90 degrees，go down this course for 1 mile；Then alter 90 degrees to starboard and go down this course for 2 miles；Then alter 90 degrees to starboard and go down this course for 2 miles；Keep adding 1 mile ever time you alter to starboard．This operation is（）search pattern
A.Williamson Turn B.Parallel C.Sector D.Expanded
单项选择题 Course directed by the OSC or CSS to be steered at the beginning of a search is（）.
单项选择题 Changing rescuers while carrying out artificial respiration should be done（）.
单项选择题 An uncontrolled flow of gas，oil，or other well fluids into the atmosphere is called a（）.
