高速和野蛮操作舱盖均是危险的。（）

单项选择题我们每航次拆卸一次吊杆。（）

A. We dismantle the jumbo boom twice a voyage.
B. We dismantle the derricks once a voyage.
C. We examine the derricks once a voyage.
D. We dismantle the heavy derricks once a voyage.

单项选择题每一个舱盖由两个或更多的盖板组成。（）

A. Each hatch consists of two panels.
B. Each hatch cover consists of two panels.
C. Each hatch consists of two or more panels.
D. Each hatch cover consists of two or more panels.

单项选择题这些舱盖通常是用电力或液压驱动的。（）

A. These hatches are usually driven by electric or hydraulic power.
B. These hatch covers are usually driven by electric or hydraulic power.
C. These hatch covers are usually driven by electric.
D. These hatch covers are usually driven by hydraulic power.

单项选择题船舶的舱盖有多种类型。（）

A. There are several types of hatch covers on board ship.
B. There are several types of hatches on board ship.
C. There is one type of hatches on board ship.
D. There is one type of hatch covers on board ship.

单项选择题开关舱的工作通常是由船员来做。（）

A. The work of opening and closing hatches is usually done by crew members.
B. The work of opening and closing hatch covers is usually done by crew members.
C. The work of opening hatch covers is usually done by crew members.
D. The work of closing hatch covers is usually done by crew members.