单项选择题 The oil is drawn from a drain tank through （）, one of a pair of pumps, into one of fine filters.

单项选择题 The needle valve will open when the fuel pressure acting on the needle valve （） exerts a sufficient force to overcome the spring compression.

单项选择题 The needle valve in the injector （） at a pre-set pressure which ensures that the fuel will atomize once it enters the cylinder.