十万个为什么·科学阅读30篇（6）

1 Why Do Rainbows Appear After Rain? 为什么雨后会出现彩虹？ 2 How Do Plants Make Their Own Food? 植物怎样自己制造食物？ 3 Why Does Ice Float on Water? 为什么冰能浮在水面上？ 4 What Makes the Sky Blue? 天空为什么是蓝色的？ 5 How Do Magnets Stick to Some Metals? 磁铁为什么会吸住某些金属？ 6 Why Do We Yawn When We Are Tired? 人困倦时为什么会打哈欠？ 7 How Do Bees Make Honey? 蜜蜂怎样制造蜂蜜？ 8 Why Do Leaves Change Color in Fall? 秋天树叶为什么会变色？ 9 How Do Volcanoes Erupt? 火山是怎样喷发的？ 10 Why Do We See Stars at Night but Not in Day? 为什么白天看不到星星，晚上却能看到？ 11 How Do Bats Find Their Way in the Dark? 蝙蝠如何在黑暗中找到路？ 12 Why Do Apples Turn Brown After Cutting? 切开的苹果为什么会变褐色？ 13 Why Do Some Flowers Close at Night? 为什么有些花在夜晚会闭合？ 14 How Do Ants Build Strong Underground Homes? 蚂蚁如何建造坚固的地下家园？ 15 Why Does Fog Form Near Rivers in the Morning? 为什么清晨河面附近容易起雾？ 16 How Do Crickets Make Their Chirping Sound? 蟋蟀是如何发出鸣叫声的？ 17 Why Do Some Clouds Look Like Fluffy Cotton Balls? 为什么有些云看起来像蓬松的棉花球？ 18 How Do Seeds Know When to Start Growing? 种子是如何知道何时开始发芽的？ 19 Why Do Some Rocks Glow Under Ultraviolet Light? 为什么有些岩石在紫外线下会发光？ 20 How Do Fireflies Produce Their Own Light? 萤火虫是怎么自己发光的？ 21 Why Do Deserts Get So Hot During the Day? 为什么沙漠白天会变得非常热？ 22 How Do Raindrops Form Inside Clouds? 雨滴是怎样在云中形成的？ 23 Why Do Ocean Waves Always Move Toward Shore? 为什么海浪总是向岸边移动？ 24 How Do Butterflies Taste With Their Feet? 蝴蝶是怎么用脚尝味道的？ 25 Why Do Some Trees Lose Leaves in Winter? 为什么有些树在冬天落叶？ 26 How Do Bees Know Which Flowers Have Nectar? 蜜蜂怎么知道哪些花有花蜜？ 27 Why Does Salt Melt Ice on Roads? 为什么盐能让路面上的冰融化？ 28 How Do Mountains Form Over Millions of Years? 山脉是如何经过数百万年形成的？ 29 Why Do We Feel Thirsty After Eating Salty Food? 为什么吃完咸食后会觉得口渴？ 30 How Do Tides Change Twice Every Day? 潮汐为什么每天变化两次？