单项选择题 My ship’s engine responds well to telegraph orders and takes about 80 seconds to reverse from full speed ahead to full speed astern.This sentence（）.

单项选择题 Most medium and slow speed diesels are started by what medium?（）

单项选择题 Many sheath-screw davits have markings to indicate the maximum angle to which they should be cranked out. If the angle is exceeded，the davit（）.