单项选择题
I am adjusting the derrick. It is a little higher.()
A.我正在修理吊杆,它有点高。 B.我正在调整吊杆,它稍微低了点。 C.我正在调整吊杆,它稍微高了点。 D.我正在修理吊杆,它有点低。
单项选择题 Cargo handling gear is the most important deck fitting.()
单项选择题 Must we unload the light cargo first?()
单项选择题 The parts of the derrick are: derrick boom rest, gooseneck, center guy, stay, topping lift, topping lift block and so on.()