单选题 Ship propulsion normally occurs with the help of a ______, which is the term most widely used in English, although the word "screw" is sometimes seen, inter alia in combinations such as a "twin-screw" propulsion plant.

单选题 Large, slow speed, two-stroke marine diesel engines are directly coupled to propeller and do not require a ______.

单选题 Medium speed engines are used widely as ______ engines in most merchant cargo ships.

单选题 Most ships that do not need a particularly good manoeuvrability, such as ocean-going container ships, tankers and bulk carriers are equipped with a ______, as it offers the highest efficiency.

单选题 The low speed diesel engines are tall to allow for long strokes which improve engine ______.

单选题 The main operating characteristic of diesel engines which distinguishes them from other internal combustion engines is the ______.

单选题 The influence of frictional and residual resistances depends on how much of the hull is ______ the waterline, while the influence of air resistance depends on how much of the ship is ______ the waterline.

单选题 The ______ engine is used for alternators and sometimes for main propulsion with a gearbox to provide a propeller speed of between 90 to 120 r/min.