英语翻译It is effectively a super-premium grade with an equivale

英语翻译It is effectively a super-premium grade with an equivalent pump (or “anti-knock”) rating of 100 octaneFor these reasons and more,avgas has a much higher octane rating than petrol blended for cars.It is effectively a super-premium grade with an equivalent pump (or “anti-knock”) rating of 100 octane.It also has a much lower,and more uniform,vapour pressure than petrol—to prevent the fuel from vaporising as the air pressure drops with altitude.“Vapour lock” (bubbles) in the fuel-line can starve an engine,causing it to stall and the plane to fall precipitously out of the sky.All told,avgas is an expensive brew costing around $5 a gallon in the United States and $9 or more in Europe这是原文，供参考，不用翻译~