One of the hottest places on Earth is Death Valley. It's a desert valley in North America. The animals in Death Valley don't use technology to keep cool. They have special abilities that help them live there.

    During the day in Death Valley, it gets hotter than 100°F. The kangaroo rat rests all day in a hole in the ground. It covers the hole with grass to keep out the heat. The kangaroo rat comes out at night when it is cooler. This little rat is also very good at saving water. It gets all the water it needs from the food it eats. The Sun makes the desert sand very hot. One snake, called the sidewinder, can solve this problem. When it travels, the sidewinder bends (弯曲) its body into a "W" shape. Then it uses the bottom parts of the "W" like legs and walks sideways (向一侧). That way it touches only a little of the sand at a time, so the hot sand doesn't bum the snake. This strange way of moving is how the sidewinder got its name.

    A lot of water in the desert is too salty for most animals to drink. One kind of fish, the desert pupfish, can live in these salty water because it can drink the salt water.

    The kiwi lives only in New Zealand. It is a very strange bird because it can not fly.

    The kiwi is the same size as a chicken. It has no wings or tail. It doesn't have any feathers(羽毛)like other birds. It has two feet and each foot has four toes. Its mouth is very long.

    A kiwi likes to have a lot of trees around it. It sleeps during the day because the sunlight hurts its eyes.

    It can smell things with its nose. It is the only bird in the world that can smell things. The kiwi's eggs are very big. There are only a few kiwis in New Zealand now. People never see them. The government says that people can't kill kiwi. New Zealanders want their kiwis to live.

    There is a picture of a kiwi on New Zealand money. People from New Zealand are sometimes called kiwis.

There are many colors in nature. But do you think that a color has weight? Let's do a test.

First, put two objects with the {#blank#}1{#/blank#} weight into two boxes. Then cover the boxes. Third, wrap (包裹) one box with a red piece of paper, the other with white. Now hold the boxes {#blank#}2{#/blank#} your hand one by one. Which one is {#blank#}3{#/blank#} ? It is certain that you will think the red one is heavier. Why do you think so? A scientist did many {#blank#}4{#/blank#} and found that different colors have different weights in a man's mind.

Also, scientists say that people accept the colors they like, and {#blank#}5{#/blank#} the colors they hate. So your body and mind will be {#blank#}6{#/blank#} by using the colors you like. Or you'll be nervous {#blank#}7{#/blank#} even get ill. For example, you {#blank#}8{#/blank#} blue and hate red. If you stay in a room with red windows and wallpaper for two hours, you'll feel you have been there for {#blank#}9{#/blank#} hours. But if the room is blue, you'll feel you have been there for only an hour, And, if a person walks {#blank#}10{#/blank#} of a blue room and into a red room, his temperature will rise. That means our body temperature will change with different colors.

Every year, wildfires destroy millions of hectares of forest land. Homes are damaged, and thousands of people die. Smokejumpers help to stop this. 

Smokejumpers are a special type of firefighter. They jump from planes or are lowered by helicopters into areas that are 1 to reach by car or on foot, such as the middle of a mountain forest. They race to put out fires as fast as they can. 

At a fire site, smokejumpers first examine the land and decide 2 to fight the fire. Their main goal is to stop a fire from spreading or to slow its progress  3 ground—based firefighters arrive. Using basic equipment such as shovels (铲子) and axes(斧头), smokejumpers clear land of burnable material, like dry grass and dead trees. They carry water with them, too, but only a limited amount. 

Most smokejumpers are men. The most important factors are your height and  4 .Smokejumpers employed in the United States must be between 54 and 91 kilograms so they don't get blown away by the strong winds or get 5 when they land. 

The work is dangerous, and the hours are long. But for these firefighters, smoke jumping isn't just a job. They6 being able to jump out of planes, fight fires, and live in the forest. As 28-year-old Russian smokejumper Alexi says, "This is the best job for tough guys. "

Some people are very careful about everything they do. On the other hand, some people, especially teens, do things without thinking too much about the results. Why is this? 

Anna, a psychologist uses computer games to find out why some people are more likely to take risks. In one game, players are asked to click(点击) on a balloon on a computer screen. Every time they click, the balloon gets bigger. The bigger the balloon is, the larger the prize will be. But if the balloon gets too big, it'll be broken and the player will get nothing. 

Anna found that when teens played this game, a part of their brain called the striatum (纹状体) would become more active. It makes teens want to win. Another part of the brain, the prefrontal cortex (前额皮质), helps them control their decision-making process. 

It turns out that young people have more striatums and less prefrontal cortexes, which affects their ability to make careful decisions. You might have already guessed that teens break more balloons during the game than adults – mainly because they like to take risks more and don't take the time to think carefully. 

"The teen brain is like a car with a very strong engine, " Anna said. "Its brakes (刹 车) just don't work as well. "