单项选择题
What is the purpose of the limit switch on gravity davits?（）
A.To cut off the power when the davits hit the track safety stops B.To stop the davits from going too fast C.To cut off the power when the davits are about 12 inches or more from the track safety stops D.None of the above
单项选择题 What is the most important difference between the bow type anchor shackle and the D-type anchor shackle? （）
单项选择题 What is the function of an air receiver in the compressed air system on a ship? （）
单项选择题 What is the female section of a tool joint called? （）
