When you get to the beach, the sand and the rocks are so hot that they hurt your bare feet. You put on sneakers in a hurry. The water is so bright and shining in the sun that you can hardly look at it. While the charcoal (木炭) fire is starting to burn in the cookout stove, every one goes for a swim. The water feels goodwarm at the top, but cooler down around your toes.
A little wind is blowing when you come out. The fire isnt quite ready for cooking yet, so you play tag or read.
For lunch there are hot dog, corn, salad and rolls, sodas, fruit, and coffee for the adults. By the time the coffee water boils and the corn and hot dogs are cooked, all the bathing suits are dry. So are the towels spread out on the rocks, in the sun.
Lunch is good. Just as you are finishing, it starts to rain so you pack up and run. But nobody minds the rain. It will cool things off.
At the same time you were having fun at the beach, work was being done. Energy from the sun was doing work. Energy, in one form or another, does all the work in the world.
Heat energy from the sun dried the towels. It heated the sand and the rocks, the water and the air. It even made the rain and the wind. Heat from the sun does small work and big work, all over the earth.
Light energy from the sun was working on the beach too. It supplied the daylight.
It lit the earth and made the sand bright and the water sparkling.
The sun also supplied the energy that grew the food you ate.
Plants use light energy from the sun to make food for themselves. The food is a kind of sugar. It is also a kind of energy called chemical energy. Green plants change light energy from the sun into chemical energy.
Plants use some of that energy for everyday living and growing. They store the rest in their leaves and seeds, in fruit, roots, stems, and berries.
The salad and the corn, the rolls, fruit, and coffee all came from plants. You and all animals depend on plants for food.
The charcoal you used for cooking began as a plant too. Once, that charcoal was a living tree that used sunlight to make food and then stored part of the food it made. The energy in this stored food remained, even after the tree died. You used that energy when you burned the charcoal.
代词精讲(16)
以-ly 结尾的形容词
英语讲义【43】名词数目错误处处
代词(一)
数词(二)
英语讲义【2】动词的运用有学问
英语讲义【32】形容词后缀不可乱加
英语讲义【31】代名词不出错
形容词及其用法
代词精讲(19)
英语讲义【33】省一省,句子更简练
英语讲义【20】“义同形异”的常用词
英语讲义【18】特殊句子的被动语态
英语讲义【54】具副词功能的过去分词短语
英语讲义【15】无须冠词的名词
英语讲义【9】动词形态不对应
英语讲义【29】句子转折词的桥梁
英语讲义【28】人称代词主格与宾格的选择方法
英语讲义【48】"Let"引导的祈使句
英语讲义【21】连接词及其用法
英语讲义【55】形容词的位置
代词精讲(9)
名词的格
代词精讲(7)
英语讲义【6】动词主语别忘了呼应
英语讲义【17】读上看下,猜猜词义
英语讲义【12】通过联想学英语
名词复数的不规则变化(一)
冠词位置(二)
零冠词的用法(二)
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |