单项选择题
A.red triangle with the letter R
B.white triangle with the letters RG
C.green square with the letter G
D.white square with the letter GR
单项选择题 When connecting the tow bridle to a tug, the end of the bridle is passed with a（）.
单项选择题 According to MLC,the minimum hours of rest shall not be less than 10 hours in any 24-hour period,and（）hours in any seven-day period.
单项选择题 （）directly affect the fitness and ability of a seafarer to perform watchkeeping duties.