香蕉为什么容易发黑腐烂?
时间：2019-02-16 作者：英语课 分类：英语听力广播—Listening
英语课
Y: So Don, yesterday I was walking down the produce aisle 1 when I saw it--long, ripe,yellow. The perfect banana. It really looked delicious and I had to have it. I took it home and hung it on a banana hanger 2. The very next morning, it developed nasty brown spots.
D: And you're wondering what gives.
Y: Right. It was a good banana yesterday. What happened?
D: It's no mystery, Yael. Those spots are a natural part of the ripening 4 process. You see, just like all fresh produce, your bananas are alive.They're taking in oxygen to help them convert sugars into energy, and releasing carbon dioxide. This process is called respiration 5.
Y: I don't know, Don, this banana looks dead to me.
D: Now, the quicker a fruit or vegetable respires, the quicker it ripens 6. For most fruits,the respiration rate slows down after the initial growth stage and the fruit ripens slowly. The growth and ripening process of bananas, however, is different. Although at first the banana's respiration slows down too, when it's ready to ripen 3, the banana's pulp 7 releases a chemical that increases respiration. This converts the starches 8 in the banana to sugars and gives it its fabulous 9 taste. And you know how good bananas taste!
Y: Watch it--you're drooling. But what does all this ripening have to do with spots?
D: Well, with all this respiration, the banana eventually processes all the starches available. And that's when it begins to die. Those brown spots are rot and decay.
Y: Poor thing. It just ran out of fuel.
D: Yeah, it's never easy seeing a good banana go bad.
n.（教堂、教室、戏院等里的）过道，通道
- The aisle was crammed with people.过道上挤满了人。
- The girl ushered me along the aisle to my seat.引座小姐带领我沿着通道到我的座位上去。
n.吊架，吊轴承；挂钩
- I hung my coat up on a hanger.我把外衣挂在挂钩上。
- The ship is fitted with a large helicopter hanger and flight deck.这艘船配备有一个较大的直升飞机悬挂装置和飞行甲板。
vt.使成熟；vi.成熟
- 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。
v.成熟，使熟( ripen的现在分词 )；熟化；熟成
- 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》
n.呼吸作用；一次呼吸；植物光合作用
- 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。
v.成熟，使熟( ripen的第三人称单数 )
- 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
n.果肉，纸浆；v.化成纸浆，除去...果肉，制成纸浆
- The pulp of this watermelon is too spongy.这西瓜瓤儿太肉了。
- The company manufactures pulp and paper products.这个公司制造纸浆和纸产品。
n.淀粉( starch的名词复数 )；含淀粉的食物；浆粉v.把（衣服、床单等）浆一浆( starch的第三人称单数 )
- You should avoid sugars and starches. 你应避免吃糖和含淀粉的食物。 来自《简明英汉词典》
- Cotton and rayon yarns are most often sized with water-insoluble starches. 棉和人造丝纱多用不溶于水的淀粉上浆。 来自互联网