十万个为什么·科学启蒙30篇（3）

1 Why Do Comets Have Tails? 彗星为什么会有尾巴 2 Why Do People Get Carsick? 人为什么会晕车 3 What Is the Milky Way? 银河系是什么 4 Where Does Salt Come From? 盐是从哪里来的 5 Why Can Magnets Attract Iron? 为什么磁铁能吸铁 6 How Does a Rainbow Form? 彩虹是怎么出现的 7 Why Do Astronauts Feel Weightless? 为什么宇航员会失重 8 Why Do People Dream? 人为什么会做梦 9 Why Do Onions Make You Cry? 为什么切洋葱会流泪 10 Why Is Flame Usually Orange? 火焰为什么通常是橙色的 11 Why Does Ice Float on Water? 冰为什么能浮在水面上 12 Why Does Hot Water Dissolve Sugar Faster? 为什么热水比冷水更容易溶解糖 13 Baking Soda and Vinegar Make Bubbles 小苏打和醋为什么会冒泡 14 Stars Seem to Twinkle at Night 为什么星星会“眨眼睛” 15 Silver Spoons Turn Dark Over Time 为什么银器会变黑 16 Hot Water Rises Up from Deep Underground 温泉是怎么形成的 17 Soda Fizzes When You Open the Bottle 为什么可乐会冒气 18 My Leg Cramps During Soccer Practice 人为什么会抽筋 19 The Sun Hits the Equator Straight On 阳光直射赤道，所以更热 20 The Moon Slides in Front of the Sun 月亮滑到太阳前面，就发生日食 21 Your Nose Sends an Emergency Signal 鼻子发出紧急信号，你就打喷嚏 22 Earth’s Axis Points Toward One Star 地球轴指向一颗星，所以北极星几乎不动 23 Your Body Turns Up the Heat to Fight Germs 身体调高体温来对抗细菌和病毒 24 Yeast Eats Sugar and Makes Tiny Air Pockets 酵母吃掉糖，制造微小气孔，面包就松软 25 My Nails Keep Growing Every Week 我的指甲每周都在长 26 The Ocean Tastes Salty When I Swim 我在海里游泳时海水是咸的 27 Mountains Sometimes Blow Out Hot Rocks 山有时候会喷出滚烫的岩石 28 Space Has Places That Swallow Light 太空中有能吞掉光的地方 29 Big Waves Can Rush In After Quakes 大地震后会有巨浪涌来 30 My Stomach Makes a Funny Sound Sometimes 我的肚子有时候会发出奇怪的声音