单项选择题
A.position the boat at the embarkation station B.lift the boat off the inboard chocks C.energize the winch for the falls D.set the brake on the winch
A.45 minutes B.1 hour and 15 minutes C.1 hour and 30 minutes D.2 hours
A.will capsize B.will incline further C.may lie at an angle of loll D.may be initially level