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.

    Smokejumpers are special firefighters. They jump from planes into areas that are difficult to reach by car or on foot, like the middle of a mountain forest. They race to put out fires as fast as they can.

    At a fire site, smokejumpers first check the land and decide how to fight the fire. They try their best to stop a fire from spreading. Using their tools, smokejumpers clear the land of burnable things like dry grass and leaves. They usually carry some water with them.

    In the US, although most smokejumpers are men, more women are joining. The important thing is that your height and weight must be within a certain range(范围). For example, smokejumpers in the US must be between 120 and 200 pounds, so they don't get hurt when they land, or get blown by strong winds.

    Smokejumpers must also be able to live in the wilderness. In Russia, many smokejumpers know how to find food in the forest and make simple tools.

    The work is dangerous, and the hours are long. But for smokejumpers, smokejumping isn't just a job. They love being able to jump out of planes, fight fires, and live in the forest. As 28-year-old proud Russian smokejumper Alexi Tishin says, "This is the best job for brave people."

    One Sunday morning, my husband and l went into a store. While paying, I heard the cashier (出纳员) say "How are you today?" as usual. I looked at her and said. "Not bad. And how are you doing?" Then I waited kindly for an answer.

    She was a little surprised at first, but then she looked sad. "My grandfather is in hospital. He has a terrible illness. I know he is 91, but…" She began to cry.

    "Don't worry too much. He will be better soon." I said.

    "Thank you!" she replied.

    Several weeks later. I went to the store again. I wanted to buy a birthday gift for my father. I saw the cashier again. I stood in her line. After the usual "How are you?", I asked quietly, "I hope this is not a bad question, but how is your grandfather doing?"

    She wondered at first why I asked such a question. Then she smiled and started telling me how brave he was. She was excited, and even after I finished paying, she kept talking, sharing her happiness with people around.

    I was surprised at how something so small meant so much to her. Taking time to listen after we ask "How are you?" is such a small action, but it is helpful and important to others!

    There's no pizza on Mars, but scientists have found a way to solve this problem for hungry astronauts: a pizza printer! NASA has developed a machine that "prints" food. They showed a model of the printer in Texas, US.

    How does it work? Cartridges(墨盒) can be filled with powdered dough, cheese, sauce, water and oil. Put these ingredients onto a printer bed. The printer bed, which gets hot from below, cooks the food as it's being printed.

    Most of the ingredients are powdered, so they call be sent into space and stored for many years without going bad. The food powder can mix with water and oil when they're being printed.

    In outer space, there are fewer choices for astronauts for dinner. Most of their foods—even things like beef—are eaten from bags as powder. Scientists hope me new food printer can be used to make more delicious food in outer space.

    The printer isn't only used in outer space. Scientists think it could be useful on Earth too. People can make meals at the dinner table according to their different needs.