单项选择题
A.to B.in C.at D.for
（）we swing the port derrick inboard?A.ShallB.AreC.IsD.B...
单项选择题（）we swing the port derrick inboard?
A.Shall B.Are C.Is D.Be
（）is the rate of discharging here?A.WhenB.WhyC.WhatD.Ei...
单项选择题（）is the rate of discharging here?
A.When B.Why C.What D.Either A or B
The （）of the derrick is out of order.A.blackB.backC.blo...
单项选择题The （）of the derrick is out of order.
A.black B.back C.block D.broken
