Green is an important color in nature. It is the color of grass and the leaves on trees. It is the color of most growing plants, too.

Sometimes, the word green means young, fresh and growing. Sometimes, it describes something that is not yet finished or plants that are not ripe.

For example, a greenhorn is someone who has no experience, who is new to a situation. In the fifteenth century, a greenhorn was a young cow or ox whose horns had not yet developed. A century or so later, a greenhorn was a soldier who had not yet had any experience in war (战争) .By the eighteenth century, a greenhorn had the meaning it has today——a person who is new in a job.

About one hundred years ago, greenhorn was a popular expression in the American west Old—timers used it to describe a man who had just arrived from one of the big cities in the east. The greenhorn didn't have the skills that he would need to live in the hard, rough country.

Someone who has the ability to grow plants well is said to have a green thumb. The expression comes from the early nineteen hundred.

A person with a green thumb seems to have a magic touch that makes plants grow quickly and well. You might say that the woman next door has a green thumb if her garden continues to grow long after your plants have died.

The Green Revolution (革命) is the name which was given some years ago to the development of new kinds of rice and other grains. The new plants produced much larger crops. The Green Revolution was the result of hard work by agricultural (农业的) scientists who had green thumbs.

    A new rubbish sorting system (垃圾分类系统) has been put into use in Fangchengyuan Community in Beijing. Local people not only sort their rubbish, but also put QR codes (二维码) on it.

    "When the rubbish is collected and the codes are seen, I will get reward points to exchange for small gifts and even some money," one of the local people told reporters. "It's really creative and encouraging."

    This smart system has been carried out in 350 communities in Beijing. The capital of China has joined a list of cities in the country that take action to support rubbish sorting. For example, Shenzhen and Shanghai have made laws to punish people and organizations for not sorting rubbish correctly.

    China produces quite a lot of rubbish every year. Much of the rubbish is buried (填埋) in soil or burned without being sorted. Landfills (填埋场) take up a lot of land and have a risk of polluting the soil and water nearby. And burning rubbish can produce harmful gases. Through rubbish sorting, we can reduce the use of landfills and air pollution.

    What's more, rubbish sorting saves resources, which could bring economic benefits (经济利益). For example, a ton of waste paper can be reused to make about 850 kg of paper, saving 17 trees and 50 percent of water. Because of the benefits, some countries have developed successful sorting systems.

    Japan has a strict and detailed system. When people throw away a water bottle, the cap, the wrapper (包装纸) and the bottle itself have to go into three different bins. Every year, families receive special rubbish sorting timetables and directions from their local governments. They are advised to follow the timetables and directions when they throw away rubbish.

    In Australia, every family is provided with three rubbish bins—the red lid (盖子) bin for "general waste" like food and plastic bags, the yellow lid bin for "recycling" like steel and glass, and the green lid bin for "green waste" such as grass and leaves. On the streets, the bins are printed with pictures of the things that are allowed inside. It makes recycling quite easy.

    Americans think much about time. From childhood they learn to {#blank#}1{#/blank#} time. They are taught to be on time to go to school, to work and to do everything. When they are having a good time, they time goes easily. When a person is dying, they say he is living on borrowed time.

    Time is money. Time is knowledge. Time is {#blank#}2{#/blank#}in America. A working American has to work hard for eight hours a day or forty hours a week. This is the working time. In his free time, he also works hard for more money. Even on Saturday and Sunday he also works hard as {#blank#}3{#/blank#}. In the street you can hardly see a man walking{#blank#}4{#/blank#}. They walk very fast. In fact, they are running.

    They love time because time can bring them money and lots of things.{#blank#}5{#/blank#}sometimes they also hate time, because they feel they have become servants of the clock.

When I was about ten, I was woken up by the shouts（喊声）of my sister one morning. She was hungry, but my mother wasn't at home, so I made a banana cake for her. Let me share the recipe with you.

What you need:

2 eggs  3 bananas  2 cups of flour(面粉)

2 spoons of baking powder(发酵粉)

1/4 spoon of baking soda (小苏打)

1/2 spoon of salt

2/3 cup of sugar

1/3 cup of vegetable oil(油)

What to do:

l  Mix(混合) together the flour, baking powder, baking soda and salt in a large bowl.

l  Add the vegetable oil. Then add a little sugar, and stir (搅拌) it.

l  Pour the eggs into the bowl and stir them well.

l  Add the bananas and stir them.

l  Turn the oven to 180℃.

l  Pour them into the oven（烤箱）. Bake（烘焙） the cake for 20 minutes.

l  Get the cake out of the oven, and cut it into pieces to eat.

Many people take running as a way to keep fit. They like to run in hot weather and enjoy the feeling of being wet through with sweat (汗) while running. Cold weather during winter months, with low temperatures and freezing cold winds, may keep people from running in the open air.

However, a new study shows that the drop in temperature is a good reason to run. In fact, running in cold weather helps improve one's performance. Many runners might find it easier to run in winter than in hot weather. The body needs less water on a cold day than in warm weather. In addition, lower temperatures reduce stress on the body. When you run in cold weather, your heart rate is lower.

John Brewer is a professor of applied sports science at St. Mary's University in London. For this study, he and other researchers put a group of people into a room where summer and winter weather conditions are recreated. The test subjects were asked to run 10,000 meters under both conditions and their biological measurements were recorded and studied.From the study, every movement runners make produces heat. The heat can be really damaging unless the body can lose it. One way in which people lose heat is by sweating. The body loses heat through sweat. The body also loses it by transporting the blood to the surface of the skin and it puts more stress on the heart, especially in hot conditions because it's much harder to lose heat when the outside environment is warm. As the result shows, running in hot temperatures results in 6 percent higher heat rates.

When running in cold conditions, the body does not have to work hard to move blood to the skin surface. Therefore, it requires less energy. The most important thing for people who run in cold conditions is to wear the right clothing. Keep as dry as possible when exercising in low temperatures. Wear warm and light clothing to keep sweat away from your skin. So don't let winter weather keep you indoors. Simply get ready for the low temperatures and start running.