Putting the Sun to Work Its a hot summer day, and you, your family, and friends decide to drive to the beach for a cookout. 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 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.
体坛英语资讯:Elkeson named in China squad for World Cup qualifiers
法总统奥朗德前女友出书痛诉被甩遭遇
国内英语资讯:China sees 105 mln tourists during Mid-Autumn Festival holiday
How to Use Free Time 如何利用课余时间
体坛英语资讯:2019/20 Figure skating season opens with ISU Junior GP
印度猴子向路人撒钱散财
研究:绿色植物能提升15%的办公效率
国内英语资讯:State Councilor stresses implementation of anti-terrorism measures
国内英语资讯:Chinese premier arrives in Russia for official visit
伊朗宗教领袖称3G网络不道德
从恋爱到婚姻:13种变化你懂的!
爱意满溢:一封皮特给朱莉的信
国际英语资讯:Assad, Putins special envoy discuss Ankaras tripartite summit on Syria
体坛英语资讯:Australian, Brazilian and British rowers shine in Hungary
国际英语资讯:Beloved giant panda Chuang Chuang dies at Thailands Chiang Mai Zoo
体坛英语资讯:Botswana women ready for South Africa clash
国际英语资讯:Iran denies U.S. claims about Saudi Aramco attacks
国内英语资讯:Beijing hosts urban planning exchange with friendship cities along Belt and Road
国际英语资讯:Iran says U.S. military bases in region within reach of Iranian missiles
中国科技行业蓬勃发展 女性发挥重要力量
体坛英语资讯:Russian teens on song in figure skating GP
健康饮食结构 低淀粉高脂肪
美国科学家制造三维模型模拟大脑功能
2019.06 CATTI备考经验:英语三级笔译二战上岸经验贴
体坛英语资讯:63 Chinese players to compete in World Skills championship
国际英语资讯:France reiterates support for Sudans transitional period
国际英语资讯:WHO provides medical supplies to southern Libya
国际英语资讯:PM Johnson on collision course with parliament as he compares Britain to Incredible Hulk
中国老人爱锻炼 外媒盛赞好榜样
囧研究 手指长度决定性格和健康
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |