【英语时差8,16】身体被冻时发生的变化（上）

Although Jack¹ Frost nipping at your nose can be the subject of happy, winter songs, actual frostbite is nothing to smile about. Frostbite occurs when your body can no longer keep your skin warm, and your living tissues begin to freeze. Here’s what happens. As the air temperature starts to drop, your body conserves² its heat by restricting the flow of blood to your skin, concentrating your warm blood inside. You’ll appear paler, and you’ll wrap your jacket more tightly around your shoulders. If the air temperature continues to drop below freezing, your exposed skin or extremities³ might become too cold. When this happens the blood vessels⁴ in the endangered areas open wide again, and blood flow increases. This extra dose of warm blood from inside your body keeps your skin from freezing, although it cools your overall body temperature.

1 jack   

n.插座，千斤顶，男人；v.抬起，提醒，扛举；n.（Jake）杰克

参考例句：

• I am looking for the headphone jack.我正在找寻头戴式耳机插孔。
• He lifted the car with a jack to change the flat tyre.他用千斤顶把车顶起来换下瘪轮胎。

2 conserves   

n.（含有大块或整块水果的）果酱，蜜饯( conserve的名词复数 )v.保护，保藏，保存( conserve的第三人称单数 )

参考例句：

• To show that the equation conserves the total volume is not difficult. 要证明该方程保持了总体积不变这点是不困难的。 来自辞典例句
• The antimuon decay also conserves the total light and heavy lepton numbers. 在反μ子衰变中，总轻轻子数和总重轻子数也是守恒的。 来自辞典例句

3 extremities   

n.端点( extremity的名词复数 )；尽头；手和足；极窘迫的境地

参考例句：

• She was most noticeable, I thought, in respect of her extremities. 我觉得她那副穷极可怜的样子实在太惹人注目。 来自辞典例句
• Winters may be quite cool at the northwestern extremities. 西北边区的冬天也可能会相当凉。 来自辞典例句

4 vessels   

n.血管( vessel的名词复数 )；船；容器；（具有特殊品质或接受特殊品质的）人

参考例句：

• The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
• All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》