We all know health is the most important in our life and we know smoking is harmful to people’s health. But not many people know about the danger of second-hand smoke.

Second-hand smoke is the smoke that comes from the smoker’s breath. If people breathe in second-hand smoke from time to time, they could get sick from it. It can cause lung cancer (肺癌) and many other diseases.

But how serious is the problem of the second-hand smoke? The World Health Organization (WHO) did a study of 194 countries. They found that second-hand smoke causes about 600,000 deaths every year. That is about 1％ of the world death and it leads to a lot of trouble and pain.

Second-hand smoke is especially harmful to children because their bodies are growing. According to a study, around 165,000 children under 5 die each year because of second-hand smoke. Most of these deaths happened in Africa and Southern Asia where health care is very poor.

You can do something to keep yourself and other people away from second-hand smoke. You can ask the smokers, such as your parents, to smoke outside. And, if someone smokes close to you, you’d better hold your breath or just walk away.

【推荐2】Have you grown taller and stronger? On Sept. 3, the Ministry of Education brought out the results of the eighth national health survey for students from elementary school (小学) through college and university. The survey comes out every five years. This year’s survey showed Chinese students’ overall (总的) health and fitness have improved since 2014.

Among all age groups, the rate for middle school students in good health saw the biggest rise up by 5.1 percentage points from 2014 to 2019. Their height and weight have increased. For example, the height of boys and girls increased 1.69 cm and 0.97 cm respectively in the age group of 13 to 15.

There was also a rise in speed and lung capacity (肺活量) among teenagers aged 13 to 15. The lung capacity of boys increased 209.7 ml, and that of girls increased 187.2 ml. Girls’ running in the 800m race improved by 4.49 seconds, while boys improved by 6.50 seconds in the 1,000m race.

Wang Dengfeng, from the Ministry of Education said that a series of education policies(政策) led to the improvement. He said these policies had helped students get more physical exercise.

【推荐3】Do you have enough sleep? With so much homework to do, it’s often difficult to get the rest you need. But you need to try, because sleep keeps you healthy and it stops you getting fat.

Recently, a group of US scientists did a study among some kids between8 and 13 years old. The study found that if kids sleep for just one more hour each day, the chance of their getting fat is cut by about 30 percent.

Why? When people don’t get enough sleep, they become tired. When they are tired, they don’t exercise enough. Also, kids like snacks. If they are awake one or two more hours each day, they have more time to eat snacks or other unhealthy foods.

So, how much sleep should kids get? Scientists say it is better to sleep 10 to 11 hours a night for kids of 5 to 12 years old. For older kids, eight to nine hours will do. (160 words)

【推荐1】When we have good news, we like to talk about it with our good friends and when something terrible happens, we make it known to others soon. But can you imagine that a tree can talk about news with each other too? Of course, no tree moves lips (嘴唇) and says words just as people do. It may sound strange, but some trees really try to talk with each other.

Willow (柳树) trees are the best-known of these trees. When insects begin nibbling (叮咬) a willow tree, the tree sends out a special smell at once. This smell tells the other willows that harmful insects are coming near. All of them quickly make a chemical (化学物质) in their leaves. This chemical is bad for the insects. The insects do not like it and they fly away soon. In this way, the willow trees protect themselves from the insects.

The next time when you take a walk in the woods, maybe the trees are talking to each other quietly.

【推荐2】It’s natural for people to talk with each other in words. Can other living things too? What about animals? The answer is surprisingly “Yes”. Some animals can use sounds and body movements to talk, and some animals can even speak words! According to the news on the New York Times, a 22-year-old elephant in South Korea could “talk”, that is, he picked up some words from his human caretakers. And pet dogs or cats can, too. A quick search on the Internet will give you a lot of short videos of dogs saying “hello”, “I love you”, and even “I want my mommy.”

Can trees talk too? Yes—but not in words. It may sound strange, but some trees really try to talk with each other in other ways. Willows（柳树）are the best-known of these trees. When insects begin biting a willow, the tree sends out a special smell a once. This smell tells the other willows that dangerous insects are coming near. All of them quickly make a chemical in their leaves. This chemical is bad for the insects. The insects do not like it and will fly away soon. In this way, the willows protect themselves from the insects.

Next time when you take a walk in the forest, listen or watch carefully. Maybe the animals or trees are talking to each other in their own ways. Isn’t nature amazing?

【推荐3】Every living thing needs to reproduce(繁殖). Reproducing means creating more members of your group. In order for plants to reproduce, they have to spread their seeds to other areas.     1    

The simplest way is gravity(重力). Many seeds are inside of fruit. When fruit gets too heavy, it falls from a tree to the ground. Sometimes animals will pick up the fruit and drop it in another area.     2     Apples spread this way.

Other plants use wind to spread their seeds. Dandelions(蒲公英) are a good example of this. Dandelion seeds are so light that when wind blows, it carries dandelion seeds to new places. Maple (枫树) seeds also use wind. Their seeds are connected with long, thin leaves that look like wings. When the seed falls from the tree, its “wings” help it fly farther from the tree.

    3     The animals eat the seeds. While the seed is in the animal’s body, it stays whole. When the seed leaves the animal, it’s in a new place.

Ants also help spread seeds. Some seeds have a special smell that appeals to ants. The ants bring the seeds back to their home, which of course is underground. They only eat part of the seed.     4     After that, the seed can start growing.