Every country in the world has a flag. A flag is a piece of cloth with a picture or pattern on it. The flag is a symbol that stands for the country. It is a custom in many places for people to fly or hang a flag. The flag tells something about the country and its culture. This may be about its land, its history, or the things that the people do there.

Many flags have patterns of stripes (条纹). The flag of Italy has a green stripe, a white stripe and a red stripe. Each stripe tells something about Italy. The white stripe is symbol of Italy’s snowy mountains. Some flags show pictures. The flag of Canada has a picture of a red maple (枫叶) leaf, which is a symbol of the maple trees in Canada. The Mexican flag has both a pattern of stripes and a picture. The picture shows an eagle eating a snake. This picture comes from a very old Mexican story.

A flag may also tell about a country’s past. The American flag is called the Stars and Stripes. It has pattern of fifty stars and thirteen stripes. The fifty stars are a symbol of the fifty states in the country, and the thirteen stripes are a symbol of the country’s first thirteen colonies (殖民地).

However, a flag may be a symbol of a group, a school, or an event like the Olympics. The flag of the Olympics shows five rings of different colors that connect. Each ring is a symbol for a part of the world that joins in the Olympics. The Red Cross is group that helps people who are in trouble. If a person sees the Red Cross flag, which has a red cross against a white background, he knows he can ask for help. People may fly a flag as a custom on a holiday. Children’s Day in Japan is a holiday when the country wishes for children’s happiness. It is a custom on this day to fly a flag with a picture of a fish.

Flags are also used as a way to talk. A flag with patterns can be very helpful to people who do not speak the same language. Sailors on ships use flags to talk to sailors on other ships. They may not speak the same language, but they know what the patterns mean. A flag with blue and white squares says “no.” A flag with five stripes that are blue, white, and red says “yes.”

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【推荐1】Plants have been on Earth for many millions of years. The first plants, evolve(逐渐形成) more than 500 million years ago, only grew in water.     1     Flowering plants only started to appear around 135 million years ago.

There are about a million types of plants.     2     In deserts, for example, many plants have very small needle-like(针状的) leaves, which lose very little water. This enables these plants to make the most of the water.

    3     Most plants use sunlight to make their own food, while animals can’t make their own food, so they have to eat plants, or other animals that have eaten plants in order to live.     4    

Plants are important in many other ways, too.     5     What’s more, we can get plenty of wood from trees. Plants’ roots also hold soil together and stop it from being washed away into the sea.

You can put a postage stamp on it, you can write an address on it, and you can send it through the U. S. mail. No, it’s not an envelope or a package. It’s the amazing coconut! The coconut is different from most other fruits because every part of it is useful. People drink the milk and eat the meat, they use coconut oil as a lotion (护肤液), and they use the husks for containers (容器). People in some island nations have even used the coconut in place of money. It is possible that humans have been using coconuts in many of these different ways for thousands of years. Even today, people are still finding new uses for the coconut.

One of the more exciting uses of the coconut is as a source of energy in place of petroleum (石油). Scientists around the world are working on using coconuts for energy because coconuts are cheap, clean, and renewable. Already, coconut-rich countries such as Papua New Guinea, the Philippines, and Vanuatu are using coconut oil for this purpose. Engineers from these countries have made an effective biofuel out of coconut oil and alcohol. The fuel can power cars, trucks, ships, and even electric-power plants. In addition, the South Pacific islands of Tokelau are using coconut oil along with solar energy as their primary energy source. The two together can produce 100 percent of the electricity the islands need.

Students at Baylor University in Texas received a grant to study the coconut husk. The result shows that coconut husks can take in water very well. Mixing coconut husks with dry soil helps the soil to hold onto more of the water. The students are also finding that the fibers can replace plastic in some cases. For example, the students are looking into using coconut husk fibers instead of plastic in parts of car interiors. If this is possible, it will help to make vehicles more environmentally friendly.

The husk of the coconut is a perfect package. It protects the coconut from damage. When the coconut falls on the ground or into water, the husk protects it. Its strong husk is the reason the U. S. Postal Service allows people to send the coconut without any extra packaging anywhere in the country. All that is necessary is to stick some stamps right onto the coconut. Each year, tourists on the Hawaiian island of Molokai post about 3, 000 of these “coconut postcards”.

Coconuts grow naturally in over 80 countries of the world. They require only sun and regular rainfall. No extra care is needed. Every year, these 80 countries produce more than 61 million tons of coconuts. It is not surprising, then, that people want to find multiple uses for the coconut. Because they’re an easy-to-grow resource, coconuts really are more than just great souvenirs to bring home after a trip to the tropics.

【推荐3】When I was a child, I liked to play on the coast of Shenzhen Bay. I used to find thin green branches. Some of those branches floated on the water, while others were in the mud on the beach, from which new branches continued to sprout (发芽). My father told me that they were the seeds of mangroves. I was surprised at their vitality and since then, I’ve been a fan of this magical plant.

In middle school, I participated together with my classmates in many mangrove-related volunteer activities such as bird watching and beach cleaning. Through those activities, I have learned that the magic of mangroves lies not only in their vitality, but also in their great role in coastal ecosystem (生态系统). Mangroves are home to a great deal of marine (海洋的) life, but human activities may do harm to them. I am proud of being a native (本地人) of Shenzhen, because my city keeps putting efforts into mangroves protection. They have become the beloved “city tree” of Shenzhen. When I ride my bicycle in winter on the boardwalk of Shenzhen Bay Park, I often see many birds flying freely above the mangroves.

It was informed that the first International Mangrove Center will be built in Shenzhen which means that my city will do something further to protect mangroves and do more research on the subject. Hopefully, there will be more activities open to the public, especially students, so that more teenagers like me can join in to protect mangroves.