文章列表

• 1.【英语时差8,16】飞机凝结尾流（下）
• To make an airplane contrail, you need water and some kind of microscopic particle for the water to condense around. When jet fuel burns, it releases ...
• 2.【英语时差8,16】生存策略（上）
• Beneath the surface of a pond or stream its a fish-eat-fish world, and the tiny minnow is often lunch for larger fish such as pike. Youd think a tasty...
• 3.【英语时差8,16】关于飞机凝结尾流（上）
• Have you ever seen a perfectly cloudless sky? Cloudlessthat isexcept for two or three long white lines smeared across the perfect blue sky by airplane...
• 4.【英语时差8,16】饥饿的“模样”（下）
• Thats because the belly on a starving person has nothing to do with fat. Rather, it is often the result of Protein Calorie Malnutrition, or PCM. PCM m...
• 5.【英语时差8,16】关于扩音器（下）
• This is because whenever a sound wave moves suddenly from a narrow space to a more open one, some of the sound is reflected backward. This is exactly ...
• 6.【英语时差8,16】关于扩音器（上）
• If you want to call to a friend half a block down a crowded street, you might cup your hands around your mouth to better aim your voice. Have you ever...
• 7.【英语时差8,16】飞盘为什么会飞？（下）
• Frisbees and compact discs have the same advantages as far as gyroscopic force is concerned, but theres another physical property that gives your fris...
• 8.【英语时差8,16】飞盘为什么会飞？（上）
• With a gentle flick of the wrist on a warm summer day, you can launch a frisbee on a long and graceful flight. Why frisbees fly so well? One reason is...
• 9.【英语时差8,16】有机蔬菜真的更健康吗？（下）
• Now, keep in mind that there may be other reasons to buy organic vegetables. Some people prefer the taste. And because pesticides and fertilizers can ...
• 10.【英语时差8,16】关于基因数据库（上）
• Where do medical scientists get tissue samples for their research? Say if youre a neuroscientist studying brain tumors; where would you find enough tu...