单选题 Today, the primary source of propeller power is the ____, and the power requirement and rate of revolution considerably depend on the ship's hull formation and the propeller design. (中)

单选题 Since the burning or combustion takes place within the engine itself the engine is known as _______. (易)

单选题 ______speed engines operate in speed ranges from 300 to 1000 rpm. (易)

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

单选题 Of all types of commercial internal combustion engines now built, which one usually gives the best performance, and hence it is quite commonly used in marine applications, especially in larger sizes? （易）

单选题 Owing to its______, the low speed cross - head diesel engine is widely used on board ship as a main engine. (中)

单选题 Diesel engines are classified as reciprocating internal combustion engines because they____. (中)

单选题 The diesel engine is a type of ______ which ignites the fuel by injecting it into hot, high pressure air in a combustion chamber. (难)