A joke about three people traveling in the desert.

There is a Frenchman, an American and an China. They are lost in the desert. Walking, I suddenly saw a lamp. The French picked it up and wiped it, and the monster came out. "I can grant each of you three wishes to express our acquaintance."

The French said, I want many women, my second wish is still many women, and my third wish is to send me home. The genie said, it is very simple.

Americans say I want a lot of money, but my second wish is still a lot of money, and my third wish is to send me home. The genie of lamps also met his requirements.

I'm from China this time. Give me a bottle of Erguotou. After a while, I finished drinking, looked at it, and then I had another bottle if I didn't drink enough. After drinking this bottle of wine, the genie asked him what was his other wish? "Oh, I miss them both. Tell them to come back with me. " The two men were having fun at home and suddenly came back.

The monster is gone.

Two people froze.

We had to set out together again and found a magic lamp as we walked. There is a lamp god coming out of it. My magic is not powerful, I can only satisfy one or two wishes of you. The Frenchman and the American are very happy. But think of just now, is this the time for China people to speak first?

The China man looked at it. Okay, I'll go first. Give me a bottle of Erguotou. Drink it slowly. Two friends were a little anxious and urged them to say what their second wish was.

China people paused, said to the magic lamp, well, it's okay, you go.

Desert mainly refers to the barren land where the ground is completely covered with sand, plants are very scarce, rain is scarce and the air is dry. Desert is also a "sand curtain", an area with drought and water shortage and scarce plants. Desert areas are mostly beaches or sand dunes, and rocks often appear under the sand. Some deserts are salt flats without any vegetation. Deserts are generally aeolian landforms. There are sometimes valuable mineral deposits in the desert, and many oil reserves have been discovered in modern times. There are few residents in the desert, and resource development is relatively easy. The desert climate is dry and it is also a paradise for archaeologists. Many human cultural relics and earlier fossils can be found.

The percentage of desert in the world: the global land area is 6.5438+62 million square kilometers, accounting for 30.3% of the total area of the earth, of which about 6.5438+0/3 (48 million square kilometers) is arid and semi-arid desert area, and it is expanding at the rate of 60,000 square kilometers per year. The desert area has occupied 20% of the total land area, and 43% of the land is threatened by desertification.

(1) "Green desert" refers to a large area of green forest, in which the trees are single in species, consistent in age and height, and very dense. The dense and single canopy completely blocks the sunlight, which makes the understory vegetation unable to grow, and the understory lacks the middle shrub layer and the ground vegetation.

It is called "desert" because the species of plants in such a forest are very single and cannot provide food or suitable habitat for many animals, so the species of animals are also very rare; Second, the forest surface vegetation is very poor, so the water retention capacity is very poor, generally dry, and it is easy to form a fire; Third, the level of biodiversity of this kind of forest is extremely low, so the ecology is very fragile, lacking the control of natural enemies to pests, and it is easy to be infected with pests, and once pests occur, it is easy to cause large-scale destruction.

(2) Hot desert and cold desert: Hot desert is a desert located in tropical areas, mainly caused by strong solar radiation and strong evaporation, and controlled by dry monsoon for a long time.

What is different from this is the cold desert, which is named because it is in a colder zone. The formation of cold desert is mainly due to the lack of precipitation in areas controlled by continental climate and the long-term control by dry and cold monsoon.

On the cold desert floor, there are large and small stones. This is because the temperature in the desert changes dramatically, and after strong weathering, the rocks change from big to small and become fragments.