单项选择题
In order to avoid shock, reduce the speed by （）.
A. control level B. control panel C. inching control D. low speed
单项选择题 According to the customs of the port, hatch covers are to be operated by （）.
单项选择题 （）lashing bar needs renewing.
单项选择题 Four （）are needed to work this heavy derrick.
