Some young people are having in the sea.

Victory must the people who never give up.

The government must people polluting the environment.

In Australia there is a famous island called Fraser Island. A great many visitors come here for holidays every year. Why? The reason is that it is special.In fact, it is the largest sand island in the world. It's about 200 kilometers long and 240 kilometers wide.

Though the island is a popular place of interest, there is no airport on the island. The long beach along the east coast works as the airport.

On the island there are sand hills without any plants, but there are forests with old trees, beautiful flowers and over a hundred lakes, too.

Every year, visitors come to enjoy the island's natural beauty. People like camping and hiking there.Animals were killed for food and this made them in danger of extinction(灭绝). They threw rubbish everywhere, and the lakes were seriously polluted.

Rules have been set up. For example, visitors are not allowed to use motorboats(摩托艇)or go fishing in the lakes, and they mustn't leave any rubbish.

Is there something strange high up in the world's tallest mountains? If so, is it a big bear? Is it a monkey? Or is it a kind of man?

No one knows. This mystery has puzzled(困惑) the world for years. In 1887, a mountain climber found large footprints in the snow. They looked like the footprints of a very large man. But men didn't walk without shoes in the snow!

In 1906, another climber saw more than footprints. Far off, he saw a very large animal standing on two legs. As he watched, it ran very quickly. Fifteen years later, newspaper had new stories about the" something". A mountain climber said he had seen the"" snowman" walk slowly across the snow, far below him. He said it looked like a very large man.

From then on, more and more people had stories to tell. But not until1951 did a mountain climber bring back pictures of large footprints. The pictures showed clearly that the snowman walked on two legs. Could it be an ape-man(猿人)?The mystery grew! Someday we may find out just what it is that makes the large footprints.

Ganquan Canyon(峡谷) in Shaanxi Province has become famous since Chang Bo posted the photos of it online. Chang never expected that his photos would make such a difference lo the canyon and the local people's life.

The area used to be covered by thick forests and there was a lot of rain. The rainwater picked up speed as it ran through the fissures(裂缝)left by earthquakes. This happened in such a way as to form the" flowing（流动的)"shapes across the surface of the rocks. Sunshine turns the rock surface into different colors, making the canyon more lively.

Yucha Village is not far from the canyon. More and more tourists go to the village. Zhou Caiye, a 59-year-old farmer of the village, set up the area's first homestay for visitors." We walk to the canyon to carry water every day. It's a big surprise that people like to visit such a boring place, "Zhou said." Nine British visitors lived in my home for nine days only to see the canyon last year. Although l couldn't speak English, I could sense how much they loved the canyon." Now, many local people work as tour guides or run homestays.

The number of visitors' cars has grown so fast that the village experienced its first-ever traffic jam(堵塞) earlier this year. The government has built a parking lot. There are also mini-buses to carry travelers to and from the canyon.

l regret some of his mistakes.

There are many unsolved mysteries in life even though science, technology, and research have come a very long way. Let's enjoy the following unsolved mysteries.