单项选择题
What is the MOST irritating to the skin?（）
A.Carbon disulfide B.Ethyl alcohol C.Isoprene D.Oleum
单项选择题 What is the（）of the turning circle in mavoeuvring?
单项选择题 What is required to launch a boat stowed in a crescent davit?（）
单项选择题 What is normally used to pass a mooring line to a dock?（）
