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(单词翻译:双击或拖选)

One day the banana is perfect- bright yellow, firm, flavourful. But even within the same day, brown spots can appear on your perfectly¹ ripe banana. Its flesh turns mushy and it's destined² for the compost or at best banana bread.

But scientists are developing a way to extend the life of ripe bananas. It's spray-on coating made from chitosan, substance found in crab³ and shrimp⁴ shells. The new gel can sprayed on bananas to slow the ripening⁶ process by up to twelve days.

Like other fruit, bananas remain alive after being picked and actually continue to respire. This means that they take oxygen and release carbon dioxide. The more the banana breathes, the faster it ripens⁷ and then rots. Bananas ripen⁵ more quickly than most fruit because they don't naturally slow the respiration⁸ after being picked, in fact it speeds up, causing bananas to become mushy.

Chitosan not only kill the bacteria on banana's skin that leads to rot, it also significantly slows down the respiration in the first place. So bananas won't drive you bananas.

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1 perfectly
adv.完美地，无可非议地，彻底地
参考例句：
The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。 Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。

2 destined
adj.命中注定的；(for)以…为目的地的
参考例句：
It was destined that they would marry.他们结婚是缘分。 The shipment is destined for America.这批货物将运往美国。

3 crab
n.螃蟹，偏航，脾气乖戾的人，酸苹果；vi.捕蟹，偏航，发牢骚；vt.使偏航，发脾气
参考例句：
I can't remember when I last had crab.我不记得上次吃蟹是什么时候了。 The skin on my face felt as hard as a crab's back.我脸上的皮仿佛僵硬了，就象螃蟹的壳似的。

4 shrimp
n.虾，小虾；矮小的人
参考例句：
When the shrimp farm is built it will block the stream.一旦养虾场建起来，将会截断这条河流。 When it comes to seafood,I like shrimp the best.说到海鲜，我最喜欢虾。

5 ripen
vt.使成熟；vi.成熟
参考例句：
I'm waiting for the apples to ripen.我正在等待苹果成熟。 You can ripen the tomatoes on a sunny windowsill.把西红柿放在有阳光的窗台上可以让它们成熟。

6 ripening
v.成熟，使熟( ripen的现在分词 )；熟化；熟成
参考例句：
The corn is blossoming [ripening]. 玉米正在开花[成熟]。来自《现代汉英综合大词典》 When the summer crop is ripening, the autumn crop has to be sowed. 夏季作物成熟时，就得播种秋季作物。来自《简明英汉词典》

7 ripens
v.成熟，使熟( ripen的第三人称单数 )
参考例句：
The sun ripens the crops. 太阳使庄稼成熟。来自《简明英汉词典》 Then their seed ripens, and soon they turn brown and shrivel up. 随后，它们的种子熟了，不久就变枯萎。来自辞典例句

8 respiration
n.呼吸作用；一次呼吸；植物光合作用
参考例句：
They tried artificial respiration but it was of no avail.他们试做人工呼吸，可是无效。 They made frequent checks on his respiration,pulse and blood.他们经常检查他的呼吸、脉搏和血液。