书城外语英国学生科学读本
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第30章 马铃薯

1.Next to bread,there is perhaps nothing which is so much used for food in our country as the potato.Yet the potato was not known in Great Britain until about three hundred years ago,when it was brought from America by a great sailor.

2.People call the potato a root,because it grows under ground.Butit is not a root;it is a knob or swelling on the lower part of the stem of the plant.

3.If we look carefully at a potato,we see little pits,or “eyes,”as they are called,on the outside.What are these eyes?Wait till the potato is planted and you will see.

4.We plant potatoes in March or April,cutting up each potato into two or three pieces,called “sets.”There must be at least one good eye in each piece or set.

5.Soon a little sprout grows out of each eye;so the eye of the potato is really the beginning of a leaf-bud.This grows up into a stem,which puts out green leaves and pretty white or purple flowers.

6.Below the ground the stem is swelling out into little beads that will grow into new potatoes for us.The earth must be piled up round the stems,so as to cover the potatoes and keep them from the light.

7.In August the stem and the leaves wither.After that we can dig up the potatoes,and we shall find that each set has given us perhaps eight or ten.

8.But does the potato plant bear no fruit?Yes;when the flowers drop off,we see little green balls,which we call “potato apples.”These “potato apples”are real fruits,with seeds inside them.

9.But if we sow these seeds,we shall only get small plants.The potatoes grown from these seeds will be no larger than marbles.

10.What is the potato made of?There is a great deal of waterin it,and the solid part is nearly all starch.You can easily make potato starch by grating down a potato in a basin of water.Strain the white water through some muslin,and let it stand till all the tiny white grains of starch sink to the bottom.Then pour away the water,and dry the starch in a saucer.

SUMMARY

The potato was first brought to this country from America.The plant is grown from sets or pieces of a potato.Out of each eye grows a new shoot.Each plant has eight or ten potatoes on it under the ground.Starch is made from potatoes.

【中文阅读】

1.在英国,我们吃得最多的食物,除了面包,大概就是马铃薯了。可是,直到300年前,英国人才认识马铃薯。当时,一位伟大的航海家把马铃薯从美洲带到了英国。①2.人们管马铃薯叫“块根”,因为它是长在地底下的。其实它不是“根”,而是植物在地下的茎上的“疙瘩”或者“膨大的东西”,学名叫“块茎”。

3.仔细看看马铃薯,能看见外面有一些小坑,也叫“芽眼”。这些芽眼是什么呢?把马铃薯种下去,你就知道了。

4.英国播种马铃薯的时间是在三四月份,把一个马铃薯切成两三块,英语叫set(s)。每块上至少要有一个芽眼。②5.很快,每个芽眼就会长出一个小芽来。原来,马铃薯的芽眼,其实是嫩芽出生的地方!嫩芽会长成茎,茎又会生出绿叶,也生出漂亮的白色或者紫色的小花。

6.地下的茎会长出小珠子一样的东西,小珠子又会长成新的马铃薯给我们吃。地下茎周围一定要堆上土,盖住马铃薯,不让它们见光。

7.八月,马铃薯的茎和叶子就会枯萎,之后我们就可以把马铃薯挖出来了,每一个种下的马铃薯块大概会长出8-10个马铃薯。

8.但是马铃薯不长果实吗?长。花落了以后,我们会看见很小的绿球,这些绿球叫“马铃薯果”。这些马铃薯果是真正的果实,里面含有种子。

9.但是如果种下这些种子,只能得到很小的马铃薯。种子长出来的马铃薯,顶多也只有玻璃球那么大。③10.马铃薯的成分是什么呢?里面有很多水分,固体的部分几乎全是淀粉。要得到马铃薯淀粉很容易:把一个马铃薯在一盆水里磨碎,把白色的水用细棉布过滤一遍,放置一段时间,直到细小的淀粉碎屑都沉到底下。把水倒掉,再将淀粉在碟子里晾干就行了。④译注①马铃薯就是俗称的“土豆”,英语是potato,属于“双子叶植物纲”“茄目”“茄科”“茄属”“马铃薯种”。这么一堆“茄子”下来,大家可能都知道了,马铃薯和茄子是近亲,实际上的确如此,茄子跟马铃薯是同一“属”,只是“种”不同。中国人一般把马铃薯当副食吃,但英国人觉得马铃薯是主食。课文里说的那个“伟大的航海家”是弗朗西斯·德雷克(Francis Drake,1540-1596),他最早是海盗出身,后来成了英国贵族,曾经在麦哲伦之后第二次完成环球航行。一般认为,1586年,他在加勒比海和西班牙人打了一仗,之后和朋友一起,把马铃薯和烟叶带回了英国。那么马铃薯是什么时候传入咱们中国的呢?可能是明朝末年,也就是17世纪上半叶。

②中国的气候,不同的地方很不一样,所以马铃薯一年四季都有种植。

③这里要补充两句:人们发现,用种子种植马铃薯,后代并不一定都是很小的,但是差异太大,长成什么样子不一定,这对农业生产是不好的,所以大部分马铃薯还是用块茎种植的。但是,20世纪70年代以后,人们克服了很多技术困难,用种子种植的马铃薯也逐渐多了起来。

④马铃薯的淀粉还有一个很大的用途,什么用途呢?你在后面会看到!

THE GLIDING SNAKE