People in southern China like famous and expensive dish—shark fin soup, but no scientific studies have shown that shark fins are good for health. So why do they eat them? Do they realize that they're killing a whole shark each time they enjoy a bowl of shark fin soup?

When people catch sharks, they cut off their fins and throw the shark back into the ocean. This is not only cruel, but also harmful to the environment. Without a fin, a shark can no longer swim and slowly dies. Sharks are at the top of the food chain in the ocean's ecosystem. If their numbers drop too low, it will bring danger to all ocean life. In fact, around 70 million sharks are caught and traded in this industry every year. The numbers of some kinds of sharks have fallen by over 90 percent in the last 20 to 30 years. Help save the sharks!

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Books                                  Contents
Leo the Snow Leopard By Craig Hatkoff	It was written by the best story-teller. The  story is about Leo, a young snow leopard(雪豹) that was helped by a kind man in the snowy mountains in Pakistan. Snow leopards are in danger. Leo was just two months old when he was found and he could not live in the wild on his  own.
Where Do Recyclable Materials Go By Sabbithry Persad	Tiana has been learning about recycling at  school. But after her dog, Bubbles, gets lost chasing after a recycling truck, she decides to learn  a lot more about recycling! Following Tiana, readers will learn how to take care of the environment.
The Scrap Kins Build By Brian Yanish	Meet the Scrap Kins. They are friendly monsters. In the book, they'll show you how to turn rubbish into some pretty cool things. Readers will learn how to make toy planes from plates, bags, old clothes and more. You know what they say: One person's rubbish is another person's love.
Explore( 探索) Life Cycles! By Kathleen M. Reilly	Do you know the largest seed( 种子)in the world or an egg can weigh up to 4 pounds? You'll learn about all of these things and more with the latest book in the Explore Your World series( 系列). The books give readers a good look into the life cycles of plants and animals on the Earth.

    MSG(monosodium glutamate谷氨酸单钠) is a food additive(食品添加剂),which has been widely used by many food factories all over the world since it appeared first in Japan in 1909.

    MSG is a substance that is added to some food to improve its taste and color. It is used in foods around the world such as cakes, bread, frozen meat, fish and vegetables. In the beginning, people thought MSG was safe just like salt and sugar. However, in 1968 some people reported they seemed to have bad reactions(反应) to MSG after having had a meal at a restaurant. They included headaches and quick heartbeat . It was also reported that MSG excited a person's brain and caused his death in Japan. Scientists think that MSG may lead to many neurological disorders(神经紊乱). In mice studies done by a university, the result showed the mice didn't want to eat the food including MSG.

    Today many food companies “hide” MSG on food labels(标签) by using different names. If you see “natural flavorings (调味品) ”,“hydrolyzed protein” and  “spices” in a food label, you are probably seeing a hidden way to “report” MSG in a food label. Every time we have a meal in a restaurant, we always feel the food very delicious to taste, but sometimes it is dangerous for our health because some harmful food additives have been added to the food.

    To protect people's health, our governments, from central to local, are taking action to stop factories producing harmful food additives.

    On July 20, 1969, Neil Armstrong became the first person to walk on the moon. The space suit Armstrong wore on his lunar mission has come to symbolize courage and human achievement. In 1971, the Smithsonian's National Air and Space Museum(NASM), in Washington, D.C., acquired (获得) Armstrong's suit. It stood proudly on display for visitors to admire, until there were changes in the suit's appearance. "Over time, the suit started to show signs of deterioration," Lisa Young said. Young is an objects conservator (文物修复员) at NASM. It is her job to preserve(维护)historical and cultural objects.

    "Plastics are tricky to conserve," Young says. They tend to degrade (降解)over time. Neoprene is one type of plastic in Armstrong's suit. The material can turn brittle and break into tiny pieces. This would ruin the space suit. NASM, seeking ways to preserve this historical treasure, removed it from display in 2006.

    What causes plastic to degrade in the first place? "Many things," Odile Madden says. Madden is a scientist in California. She explains that sunlight, water, humidity, and dust can cause plastics to degrade. "Some plastics will break down no matter what we do," Madden says.

    Yet history can still be saved. Scientists have found that storing plastics in cooler temperatures, with lower humidity levels, can slow degradation. Young says Armstrong's suit is currently in storage at a temperature of 63°F and a lower relative humidity of 30%. These conditions will be maintained when Armstrong's suit returns to a museum display case in time for the 50^th anniversary of the moon landing.

    Plastic degradation affects art, too. Artist Claes Oldenburg created False Food Selection in 1966.It consists of plastic food displayed in a wooden box. The plastic food used to look real. Now, some of it has flattened and yellowed. Georgina Rayner is a conservation scientist at Harvard Art Museums, in Cambridge. She says the artwork's wooden box produces an acidic (酸的) gas that eats away at the plastic. This speeds up the degradation process. But Rayner is motivated to conserve this artwork and others like it. "Plastics are a part of our history," she says. "It's important to preserve them so that future generations can understand the journey we've taken."

    People and dogs have been living together for hundreds of years. When did dogs and people become friends? Where did dogs come from?

    A group of scientists tried to answer these questions. They just finished a study about the history of dogs. In the study, they looked at the DNA of dogs all over the world and found that dogs, like humans, shared DNA with their family members. The scientists put together a big family tree for dogs. It went all the way back to the animal's beginning.

    In this way, scientists learned about the history of dogs. The first dogs lived in Asia. They were born about 33,000 years ago. At first, there were only about 6,400 of them. Their parents were wolves(狼).

    The new study answers many questions. It raises some too. For example, what caused wolves in Asia to become dogs all those years ago?

    One idea is that their DNA slowly changed and the wolves became dogs in the end. As time goes by, dogs became "man's best friends" Or it could happen the other way around. It was possible that some wolves started living with people before they became dogs. Living with people led to many changes to these wolves. It changed their DNA, so their offspring(后代) became dogs. In other words, it was possible that wolves were our friends before they became dogs.

    By studying DNA, scientists now have a much better understanding of the history of dogs. ________.

    How exactly dogs came to be our friends is still unclear.

    Cars make our lives more convenient. But they can also be a problem. For example, fossil fuel(化石燃料) cars mainly cause air pollution.

    To improve the environment, many countries are developing electric vehicles(EVs，电动车). Among them, China is taking a leading role and has created the world's largest EV market.

    Last year, over 40 percent of the 753，000 EVs sold in the world were sold in China, more than twice as large as the number sold in the United States.

    "Filling up a fossil fuel car with gas(汽油) is more expensive than charging(充电) an electric car, " said Wu Hao, who bought an electric car this year.

    However, there are still some problems. It can be hard to find charging piles(充电桩) and the cars can't go far before needing to be recharged.

    Some of these problems are being solved. In 2014, China had 31，000 charging piles. Now China has the world's largest EV charging network, with more than 167，000 charging piles in total.

    Developing EVs is one of many efforts that China has made to cut down pressure on its environment after the government promised to stop increases in carbon dioxide emissions(二氧化碳排放量) by 2030.

    "As China goes, so will the world's car industry，" the Wall Street Journal said. China has taken a leading role in the world's electric vehicle industry.