时差N小时 饼干的杀伤力液态气的燃点

People who work with chemicals make sure they know the flash point of each substance in their labs. A flash point is the temperature at which the fumes¹ from a liquid can be ignited with a spark.

与化学药品打交道的人，总会确保自己知道实验室中每一种物质的燃点。燃点是液态气体能被火花点燃的温度。

But people who have never taken a chemistry course need to be concerned with flash points as well. For example, the gasoline you put into your car has a flash point of minus forty-five degrees Fahrenheit².

但未曾上过化学课的人同样需要关注物质的燃点。例如，你加入车里的汽油燃点是华氏零下45度。

So, unless you live in a climate where the temperature stays below minus forty-five degrees, the fumes from gasoline can ignite from a nearby spark. And that’s why most gas stations have warning signs posted about not smoking while you fill up your tank.

所以，除非你生活在温度维持在华氏零下45度以下的环境里，汽油逸出的烟雾才不会被附近的明火点燃。这也是为什么大多数加油站都张贴警告标志，告戒人们不要在给车加油时吸烟。

Olive oil has a flash point of 437 degrees Fahrenheit. That means if you could heat olive oil to 437 degrees, it would give off a vapor³ that could ignite if a lit match passed through it. Cod⁴ liver oil has a flash point of 412 degrees Fahrenheit and formaldehyde has a flash point of 122 degrees.

橄榄油的燃点是华氏437度。这意味着如果你把橄榄油加热至437度，它散发出的蒸气完全可以被一根划过去的、燃着的火柴点燃。鱼肝油的燃点是华氏412度，而甲醛的燃点是122度。

Most flash points are inconsequential to the lay person because they occur at such high temperatures. But some, like kerosene⁵, with a flash point of 100 degrees Fahrenheit, can be cause for concern on a hot day. If you keep an old-fashioned kerosene lamp on your fireplace mantel, you probably shouldn’t light it on a hot summer day, or you might ignite more than just the wick of the lamp.

大多数物质的燃点对于业外人士来说不重要，因为它们只在高温条件下出现。但是，一些像煤油一样，燃点为华氏100度的物质，在炎热的日子里着实令人担忧。如果你的壁炉架上有一盏老式煤油灯，你最好不要在炎热的夏天点燃它，因为你点燃的可能不仅仅是煤油灯的灯芯。

1 fumes   

n.(强烈而刺激的)气味，气体

参考例句：

• The health of our children is being endangered by exhaust fumes. 我们孩子们的健康正受到排放出的废气的损害。
• Exhaust fumes are bad for your health. 废气对健康有害。

2 Fahrenheit   

n./adj.华氏温度；华氏温度计(的)

参考例句：

• He was asked for the boiling point of water in Fahrenheit.他被问到水的沸点是华氏多少度。
• The thermometer reads 80 degrees Fahrenheit.寒暑表指出华氏80度。

3 vapor   

n.蒸汽，雾气

参考例句：

• The cold wind condenses vapor into rain.冷风使水蒸气凝结成雨。
• This new machine sometimes transpires a lot of hot vapor.这部机器有时排出大量的热气。

4 cod   

n.鳕鱼；v.愚弄；哄骗

参考例句：

• They salt down cod for winter use.他们腌鳕鱼留着冬天吃。
• Cod are found in the North Atlantic and the North Sea.北大西洋和北海有鳕鱼。

5 kerosene   

n.(kerosine)煤油，火油

参考例句：

• It is like putting out a fire with kerosene.这就像用煤油灭火。
• Instead of electricity,there were kerosene lanterns.没有电，有煤油灯。