The Nile crocodile (鳄) lives in and near African rivers. It is a very large animal. It can grow up to 6 meters long. Its body is green and brown and it has a very big mouth. Most of the Nile crocodiles can live to be about 70 years old in the wild. Some can even live up to 100.

The Nile crocodiles spend most of the day on the bank (岸边) of the river in the sun without moving. At night, they go back into the water to find food. They are excellent swimmers. They can swim as fast as 30 km/h and stay up to 30 minutes under water.

As meat caters, the Nile crocodiles eat birds, fish and other crocodiles. Sometimes they even eat people. A person washing clothes by the river might just look like a delicious meal for them. Hundreds of people die because of them each year.

Now the Nile crocodiles are in danger. Do you know why? First, people kill them for their skin (皮肤) to make things like shoes and handbags. Second, people catch them for food or medicine. And sometimes they die because they hurt people. Last but not least, some people destroy their home so the Nile crocodiles don’t have enough space to live.

We usually think plants are quiet. They never speak. They can’t walk. And they can’t think like us. However, The Green Planet shows plants are just like animals. They always fight for food and light. The documentary (纪录片) uncovers the secret lives of plants.

“Plants are as competitive (竞争的) as animals,” says Sir David Attenborough, narrator of the documentary. Plants fight against each other to live. In rainforests, different kinds of plants fight for sunlight. The forest floor is a “battlefield” as only 2% of the sunlight reaches there. Each species follows its own rules to get light. Some plants spread their big leaves, but a vine (藤蔓) tries to take a free ride. Finally, a fast-growing tree catches up with them. The tree has slippery (滑的) leaves, which stop the vine from getting a hold.

In The Green Planet, we can see a wonderful world of plants. They fight, they hunt, they cheat, they communicate with each other, they protect themselves and their neighbors, and they even kill animals. The documentary also helps us know how important the natural world is to us all. “Plants are the basis (基础) of all life, including ourselves,” says Sir David Attenborough. “We depend on them for food and fresh air. The earth takes care of us, and we must do the same. It is for the next genelation.”

In China, more and more people have realized the seriousness of climate (气候) change. Many young people have been living a low-carbon (低碳) life.

Zheng Xiyu is one of them. She has been trying to reduce her carbon footprint. Every morning, she takes a bus to her office and it takes her about 40 minutes. But Zheng has been thinking of changing this. She wants to try a different means (方式) of transport — cycling. Riding a bicycle to work, the lady says, takes about the same amount of time as taking a bus. “However, it’s better for the environment and my health.” she says.

Professor Li Lin has also been leading a low-carbon lifestyle. Her office uses energy-saving lights. These lights go off themselves when they are not needed. This has saved a large amount of electricity. Another way to save energy is to double-print the paper. Professor Li says small actions like these are important for protecting the environment. “Let’s say you have saved one ton of paper. That’s about two and a half tons of CO₂.” Professor Li says.

Lin Hui always chooses products with a longer life when he shops. He says this helps to reduce waste. Two years ago, Lin and his friends set up an environment website, where he wanted to give some advice on saving energy and protecting the environment.

It’s easy to change to a low-carbon lifestyle. Everybody can do this and make a difference.