Noise pollution is doing much harm to our health now. Noise, in fact, is unwanted sound and is a kind of invisible (无形的) killer. More and more students enjoy listening to music very much. When they listen to MP3 players, they like to turn up the volume (音量). Some people love listening to loud music. Furthermore, while watching TV, they keep the volume up. But they haven't realized that the noise is weakening their hearing. In fact, the noise not only influences each member in the family, but also makes a difference to the comfort of neighbors.

Noise pollution is a source of increasing misery (痛苦) to people in our society. If people are often disturbed by it, they may feel uncomfortable or upset. What's worse, the noise can make people mad sometimes. If a worker works in a printing factory for too long, his/her hearing loss is much faster than a common person working in a quieter environment. So everybody must pay more attention to noise pollution. Generally speaking, the following four types of noise should be watched out for:

    ◆Noise in the street

    ◆Construction site (建筑工地) noise

    ◆Noise at work

    ◆Transportation noise

    I think the local department (部门) should take measures to control the noise levels, but it's everybody's duty to keep a quiet environment.

    Many people may sometimes wish it could be summer all year round. However, as nice as summer is, we really need the other seasons as well.

    Then why do we have different seasons? We know that the Earth spins on its own axis (轴线). This makes day and night. In 24 hours the Earth turns round once. When we are facing the sun, it is day. When we face away, it is night. Simple!

    We travel around the sun in a circle. So why does it get colder in winter and hotter in summer? It's because the axis of the Earth is tilted (倾斜的). It means that in summer some places, such as the UK, are leaning towards the ssun. The temperature rises. As the Earth travels around the sun, these places begin to tilt away and the temperature drops. It becomes winter.

    This is why when the UK has winter, Australia has summer. Imagine having Christmas dinner on the beach! But not all countries have seasons. Countries near the equator (赤道), the line which goes round the middle of the Earth, don't have different seasons. The weather stays almost the same temperature all the year round. Can you think why this is? The middle doesn't tilt very much, does it? This means the seasons don't change much.

    Then what about the North and South Pole? What are the seasons like there? Because they get very far away from the Sun, their seasons are very extreme. There are only two seasons near the North and South Pole: winter and summer. What's more, they only have one sunrise and one sunset a year. It is dark for six months of the year and light for six months of the year. What problems would there be if you had to live somewhere that was dark for six months of the year and light for six months of the year?

    A new camera made by a company named Netatmo has facial recognition software (人脸识别系统) that can tell parents at work that their children have returned from school, or that a package (包裹) has been taken to their home. It can also tell them if a stranger has entered their home.

    Janina Mattausch is a product marketing manager for Netatmo.

    "The common security (安全) cameras at present are not that smart. So, they can tell you if something is moving but they don't necessarily know if it's a human being or, ah, if it's your kid- they don't know the difference, so they will warn (警告) you all the time."

    When family members enter a home, the new camera "recognizes" (识别) them and sends information to the owner's smartphone. The owner can choose to see the video then or later. But if an unknown person enters a home, the camera will send the owner a warning that will cause an alarm to sound on the owner's smartphone.

    That is what happened recently to a smart home camera owner named Damien. He lives in Paris.

    "On a Friday I was at work, attending a big monthly meeting when my phone warned. At first I told myself 'Oh, it must be a mistake, maybe I have to set the system again.' —but the notice on my phone was telling me that there was a movement in my flat and also a face that the software did not recognize."

    He watched the video and was very surprised by what he saw.

    "I saw a person I did not know with his shoes on. I was watching it live on video. So I felt totally unbelievable, frozen. I asked a workmate to take me back home as fast as possible and I called the police on the way."

    With the help of the video, the police found the intruder (闯入者) later that day.

    The weather has always been much talked about in our daily life. But bad weather is sometimes hard to stop, no matter who he is-rich or poor, young or old-in every part of the world. Maybe that is why there are so many expressions about the weather, especially about rain

    Sometimes, when you need rain, you do not get any. Other times, you get rain when you don't want it. Take a football game for example. A sudden heavy rain can stop a wonderful game, making the players and the 20, 000 persons watching the game run for cover. If the game can't go on, people who have bought the tickets are given "rain checks". These are special tickets that will let them watch a later game for free.

    "Rain checks" now means a second chance at something. Often, a rain check has nothing to do with rain.

    Shops may give you a "rain check" when they sell something all out-a TV set, for example at a special low price. After all the TV sets are gone, the shop gives rain checks to those who wanted to buy one. The rain check lets a person have another chance to buy the TV set later, at the same low price, after the shop receives some more from the factory

    "Rain check" is also used in our daily life. It's a way of accepting invitation, but for a later time. You may ask for a "rain check if you are asked to a friend, s house for dinner, but can't be there. You say, "T would love to join you for dinner, but I'm busy. Could I have a rain check?" You are asking, in other words, if you could join your friend for dinner at another time.