单项选择题
Don’t operate two or more hatch （）at the same time.
A.caps B.levers C.covers D.coamings
单项选择题 （）-speed operation and rough handling of covers are dangerous.
单项选择题 In order to avoid shock, reduce the speed by （）.
单项选择题 According to the customs of the port, hatch covers are to be operated by （）.
