单项选择题 Under the IALA-A Buoyage System，a green spar buoy with a triangular topmark would indicate that the buoy（）.

单项选择题 Under normal weather and sea conditions when securing a stack of containers with twist locks，lashings are required when the tier exceeds what height? （）

单项选择题 To turn over a liferaft that is floating upside down，you should pull on the（）.