;Why do old books turn yellow?Why do old books turn yellow?为什么旧书会变黄？为什么旧书会变黄？Most paper is made from..., such as Beijing and Shanghai.The sun is more than 4.6 billion (十亿) years old.About 90 percent of people on Earth ……

为什么书页会随着时间变黄？Do you have some old books at home? Take a look at them. You may find that the pages look a bit yellow. Why does old paper turn yellow?Your books don’t turn yellow by themselves ……

autumn. But did you ever wonder how and why this happens? To answer the question, first you have to understand what leaves are and what they do.Leaves are nature's food factories. Plants take water ……

Changing colour in the autumn秋天树叶为什么会变黄呢?Q:Why do leaves change colour in autumn?A:The beautiful... disappears. As a result, its yellow, orange and brown colours can be seen. ……

望it's hopeful that .... ……有希望ExercisesExercises1. Which photo impressed you the most? Why? Share with your classmates.1. Which photo impressed you the most? Why? Share with your classmates.Jump into the new ……

a hu look like?_______________________________________2. What did ministers do with the tablets?1) ____________________________________2) ____________________________________2. What did ministers do ……

them. So you focus on the work you do now and accept what life is. H.  You are rational (理性的) and helpful. You have many dreams but fail to achieve them. So you focus on the work you do now ……

亚文化之下的年轻人如何装扮自己？Do you find teenage fashion hard to understand? Me too. That’s why I asked my 15-year-old niece Hannah to help me find out more about teenage fashion.l The goths 哥特风The goths are easy ……

changing. Their green leaves turn red, orange, yellow or brown. Then the leaves fall off completely... on those sorts of trees do.Think of leaves as the kitchen of the tree, the place where food is prepared ……

-lined streets turn flaming (热烈的) yellow and the skies are often clear, is even more beautiful...’s parks and gardens suddenly turn green and its cherry (樱花) blossoms and magnolias (玉兰花) bloom ……

that they are yellow or brown. But why does old paper turn these colors?Most paper is made from wood, which...The pages of old books look yellow or brown. TNSThe pages of old books look yellow or brown. TNS随着 ……

. Meanwhile, my teachers also asked us to read books. They seem boring but helpful. What should I do... also asked us to read books. They seem boring but helpful. What should I do?- Yin- YinA:A:Dear Yin ……

YOU'VE read about history in books, right? Well, some US kids like to act out the stories... year I was amessenger(传令兵). I carried messages for our army," says Alex. When Alex is old enough, he ……

纸质书的魅力为何经久不衰？Why do the world’s youth continue to buy paper books, rather than read e-books on their favorite electronic devices? ……

these things that makes the beautiful colors we enjoy during autumn.?11. Why do leaves change color...-dressed citizens 2. How do you understand the sentence “Both men and women look like they stepped out ……