Weather has a strong effect(影响) on people. It influences health, intelligence (智力) and feelings. In August, it is very hot and wet in the southern part of the United States. People there easily have heart trouble and other kinds of health problems during this month. In the Northeast and the Middle West, it is hot at some times and very cold at other times. People in those states will have heart trouble after the weather changes in February or March.
      The weather can also influence intelligence. For example, in a 1983 study by scientists, the IQ scores of some college students were very high during storm, but after the storm, their scores were low. Storms can increase intelligence. Very hot weather, on the other hand, can decrease(减少) it. Students in many schools of the United States often do badly in exams in the hot months of the year(July and August).
      Weather also has a strong effect on people's feeling. Winter may be a bad time for thin people. They usually feel cold during these months. They might feel depressed during cold weather. In hot summer weather, on the other hand, fat people may feel unhappy. At about 65F, people become stronger.
      Low air pressure(气压) makes people feel free, but it also increases forgetful- ness. People leave more bags and umbrellas on buses and in stores on low pressure days. There is a“perfect weather”for work and health. People feel best at a tempera- ture of about 64F with 65 percent humidity(湿度).
      Are you feeling sick, sad, tired, forgetful, or very intelligent today? The weather may be the reason.

    Is your TV connected to the Internet? What about your chair, or your fridge? Probably they are not. But in the future, most things in your home may be connected, thanks to the so-called "Internet of things".

    The Internet of things may be coming sooner than you think. Earlier this year, A Samsung CEO spent a lot of time talking about the Internet things. He said that five years from now, every Samsung product will be part of the Internet of things, no matter whether it's a remote control or a washing machine.

    So, how do household(家用的) objects that are part of the Internet of things work? Well, think of a common chair. When connected to the Internet, the chair warms up when it knows the user has just walked into the room and is feeling cold.

    An Internet-connected camera could help people feel safer in their homes. It can know people's faces and has an infrared sensor(红外传感器), so even if it's dark it can see when someone passes by and send you a message on your smartphone to let you know who's there. If the person is someone you don't know, it can tell you that, too.

    But according to MIT Technology Review, whether companies are connecting dog food bowls or security systems to the Internet, there may be some problems. For example, many early connected-home objects don't have much built-in security, which means they could be hacked(被黑客攻击). Moreover, it could be difficult to get these new machines to work together especially when they are made by different companies. To fight this, many companies have joined the Open Interconnect Consortium, which had 45 members by late 2014.

    So, picture this: you enter your home. The temperature changes to make you feel comfortable. Your favorite music starts playing for you. Do you think that this would be a good thing? It may happen sooner than you think.

    Not many years ago, some farmers were worried because hawks ( 鹰) were taking many of their chicken. The farmers didn't know what to do. Finally they went to the country officials and asked for help.

    "Kill the hawks," the officials said. "We will even pay for them." So the farmers began to think of ways to kill the hawks.

    The farmers killed many hawks. They no longer had to worry about their chickens. But they now had a new worry. Field mice were eating up a lot of the farmers' grain.

    How did this happen?

    Hawks cannot only chickens but also field mice. They eat more field mice than chickens. But the farmers didn't know this. When they killed a lot of hawks, they changed the balance.

    When people move into a new place, they often destroy many wild plants. Often these plants are food for the animals. If the animals can't find enough plants to eat, they will starve or have to leave the place.

    In one part of the USA, for example, the deer there like to eat a certain kind of wild roses. The mountain lions there eat the deer. The number of deer, mountain lions and wild roses doesn't change much if people leave things as they are. But people killed many mountain lions in order to protect the deer. Soon there were so many deer that they ate up all the wild roses. Then the deer began to eat the green leaves of young trees. These trees were important to the farmers. So the farmers thought of ways to protect their trees. Now the deer had nothing to eat, and many of them died. This was another lesson from nature.

    To keep the balance of nature is important for us to remember.

    In many places the weather changes during the year. These changes are called seasons. In the north and south there are four seasons in a year. At the North and South Pole, there are only two seasons. In tropical (热带) places near the Earth's equator (赤道), there are two seasons: a 'wet' season and a 'dry' season. Each season brings changes. They are important for plants and animals that live in different parts of the world.

    Spring starts when the day and night are the same length. The weather gets warmer and sunnier. Trees and plants start to grow. Many animals have their babies in spring.

    Summer begins on the longest day of the year. In the north this is on June 21 or 22. Summer is usually the warmest and sunniest time of the year. Fruit grows faster on trees and plants. Young animals grow bigger and stronger.

    Autumn starts when the day and night are the same length again.

During autumn, the leaves change color and fall down from the trees. Some animals collect food before winter comes.

    Winter begins on the shortest day of the year. In the north this is on December 21 or 22. The weather is colder and in some places there is lots of snow. Plants and trees stop growing. Some animals, like bats and bears, find places to hide and sleep. This is called hibernation.