单项选择题 Whether a ship is sailing before the wind or sailing in the rough sea, we must reduce the fuel injection of the main engine.For the former one, it aims to prevent the main engine being（）, while for the later one, it aims to prevent the main engine being（）.

单项选择题 While sailing under normal weather and sea condition, the basic parameter which is used to restrict the fuel injection of main engine is （）

单项选择题 If keep the fuel injection of main engine unchanged when ship is fouled, that will causeⅠ.The speed of main engine to be reduced Ⅱ.Ship speed to be reduced Ⅲ.The resistance torque of propeller to be increased Ⅳ.Trim at stern to increase（）