There are many deserts (沙漠) on the earth. And the following are some facts you may find interesting.

What are deserts like?

Deserts can be hot and dry places. Rain may not fall there for months or years. Some deserts are sandy and stony (多石的). Deserts can also be very windy places. The wind can change the shape of the deserts. It moves sand around from place to place.

Temperatures in the desert can vary enormously(非常). During the daytime, the temperature may reach 40℃ even in the shade (阴凉处). At night, deserts can become very cold. In winter there may even be a frost (霜冻) in the early morning.

Living in the desert

The camel is sometimes called "the ship of the desert". It stores food in its hump (驼峰) and can go for days without water. It has large feet which help it not to fall into the soft sand. Its long eyelashes (睫毛) keep out the sand during sandstorms.

An oasis is an area of the desert where water may be found. The water may be in pools or under the ground. People and animals visit an oasis for water and food. Plants grow at an oasis. Some farmers are able to grow crops here.

The Arabian Desert

The Arabian Desert lies between the Red Sea and the Arabian Gulf. In some parts of the desert, it is too hot for people to live. Oil was discovered under parts of the desert and in the Arabian Gulf. This oil has made some countries in the area very rich. Much of the money has been spent building fine cities with lovely parks and lakes, and people live a comfortable life there.

Science shows why we trust people who are confident. Imagine this: one person tells a lie confidently, while another says something true in a hesitant voice. Which person would you trust?

According to British scientist Dean Burnett, humans are far more likely to believe information expressed confidently by a confident person or in some other ways using confident language. "Humans trusting confident people over those who are more uncertain is a known thing," wrote Burnett for Science Focus magazine. "When two people are trying to make a decision but each person says different things, confidently expressed arguments are seen as passing on better information, which decides the decision."

Why is this the case? As Burnett said, humans are social animals. In our ancient past, most of our information about the world came from our tribe(部落), in other words, the people around us. So, if ancient humans heard someone confidently saying "There's a tiger coming" , believing what that person said could save our lives.

On a more personal level, we use our own experiences to understand what other people do and say. That's how our brain works. When we are confident, it's for good reason. Therefore , we believe that when someone else is being confident, they must have good reason, too.

However, we need to realize that confidently expressed information may be more persuasive(有说服力的), but that doesn't mean it's correct. As Burnett wrote, we are living in a more and more different world. Trusting very confident people without checking the facts can lead to "unexpected results".

Some animals can easily find their way home after a long journey. How do they make it? Scientific research shows that they are born with certain unusual abilities for direction.

A certain kind of ants, for example, can count their steps to avoid getting lost. They can go as far as 110 metres and bring food home. These ants live in the open desert (沙漠), so they have nothing to guide them along the way. It's like someone walking six kilometres through a dark forest.

Some fish have an unbelievable sense of smell. They can smell even a single drop of their home water in a large sea area. Some sea birds have a similar ability. They are able to make a smell map of their flying area.

Some animals can sense the earth's magnetic field (磁场), while humans can't. This magnetic field guides a certain kind of fish when the swim a long way to a place and then back. How can this kind of fish do that? It is still a____mystery. Scientists have no good answers yet.

However, animals with such unusual abilities still have difficulty dealing with environmental changes caused by human activities. For example, many birds depend on stars for direction, but they get lost easily a night when city lights are kept on all night. To solve this problem, we can simply turn off some lights at night. Clearly, one small act of humans may mean a lot to animals.