Dinosaurs weren’t the only animals that lived millions of years ago. Other creatures also lived on Earth. But then a huge planet hit the Earth. Dust from the explosion (爆炸) filled the air, forming cold and dark environment for living things for a long time. Green plants died, so animals could not find food. Most of the dinosaurs died out, but some fish and birds were still alive. One of them was a large fish called a sturgeon.

Most sturgeons live in rivers and lakes. They are bottom-feeders. They eat small living things that live in the sand and earth. Even in the very cold weather, sturgeons can find food. In this way, they have lived on for millions of years.

The past 100 years have brought a new challenge for these fish. People around the world like to eat delicious eggs of some fish. These eggs are called caviar. The most popular kind of caviar is sturgeon eggs. Since people ate millions of sturgeon eggs, few babies were born.

By the 1990s, sturgeons almost disappeared. New laws stopped overfishing and controlled the selling of caviar. Protections like these help sturgeon’s population grow again, but it will take a long time. These ancient fish have been around millions of years. _________

On the side of the road in the Hoh Xil Nature Reserve in Qinghai Province, you might see a fat wolf. It wags (摇摆) its tail in front of the passing cars. It hopes to get a meal.

It’s said that the old hungry wolf was forced to leave the wolf pack (群体) a few months ago because it was not good at hunting (猎食). So, the wolf was skin and bones. But that all changed after a driver gave it two pies and posted a video of it online. The video made the wolf very popular, and a lot of people came to the area to give food to it.

After that, the wolf waits for passers-by’ snacks every day. But the food people gave it are high in oil, sugar and salt, such as pies, roasted chicken and sausages. Later, more wolves have joined this behavior. The wolf’s change makes it look like a pet dog. But the change means that it is losing its ability to live in nature, and that may cause the wild animal to die.

In fact, it is common for wild animals like wolves and bears to be fed (被喂养) near the roads in the province. People care about wild animals, but their feeding sometimes can be bad for both animals and themselves. If a wild animal needs help, people should ask for the government’s professional handling (专业处理).