Find Which Direction Is South

    Do you have a good sense of direction? If not, please take with you a compass. But if you forget to take a compass, you can still find your way.

    It's never a good idea to imagine that the family member who was entrusted (委托) with the job of map-reading actually knows where the family is. You can tell by the slightly confused load on their faces that nothing on the ground seems to match the map. Never mind. The sun is shining and it's still morning.If you don't know the exact time, you can still find out where south is, but you'll need to be patient.

    ①Find a straight stick and put it in the ground in a place where you can mark its shadow.

    ②Try to position the stick as vertically(垂直)as you can. You can check this by making a simple plumb line (铅锤线) with a piece of string and weight. You haven't got any string? OK, use a thread from your clothes with a button tied at the end to act as a weight.

    ③Mark the end of the shadow cast by the stick.

    ④Wait approximately half an hour and mark the end of the shadow again.

    ⑤Keep doing this until you have made several marks.

    ⑥The mark nearest the stick will represent the shortest shadow, which is cast at midday, when the sun is highest in the sky and pointing to the exact south.

    ⑦Pick a point in the distance along the line between the shortest shadow and the stick.

    ⑧That point is south of where you are.

    ⑨Now you can turn the map, like you did before, and find which way you should be travelling.

    ①What does the city of the future look like? Flying cars? Robots? Or smog（烟雾）-eating buildings?

    ②Arconic, an American company, has made plans to build a 4.8-kilometer-high skyscraper（摩天大楼）. It says that the super tall building can clean not only itself but also the air around it by “eating” smog and pollutants（污染物）. But how is it done?

    ③Sherri McCleary, s scientist at Arconic, says they have introduced a new technology called EcoClean. It is a special coating that pulls pollutants out of the air. With a little help from sunlight and water vapour（水蒸气），the coating will produce atoms（原子能）called free radicals（自由基）. It is these free radicals that will take in air pollutants, break them down, and then leave the air cleaner.

④But “eating” smog and pollutants is not the only thing this skyscraper is able to do. In fact, thanks to 3D printing, the materials the building used will become even better and stronger—not only making the skyscraper look more modern, but also make it possible to stand strong winds and terrible weather.

    ⑤However, some people don't think it will work out well. Air pollution has its own character and it harms lots of cities. Does the smog-eating building have such a magical ability to stop the pollution? It seems impossible to bring the pollution under control in a short time. We should prepare ourselves for a hard fight against the pollution.

    ⑥Sounds impossible? Anyway, Arconic believes a skyscraper of this kind will be built by 2062.

    Humans and animals need oxygen to exist. Without it, most living things will die. But where does oxygen come from'? Trees. Trees can take in much carbon dioxide which may be bad for our environment and produce oxygen for us to breathe.

    All people know that trees are important to us. Scientists believe humans cannot live if there are no trees on the Earth.

    Trees are a major source(来源) of food. Apples, oranges, lemons all come from trees.  Humans and animals knew how to get food from trees many years ago.

    In fact, many kinds of important medicine come from trees too. Some special things on trees can be used to produce medicine. Also, trees can make the world beautiful and relaxing. They help protect the soil.

    Did you spend much time lying on the comfortable sofa at home during the summer vacation? How often did you do sports this summer? People across the world need to get moving, according to a new study by the World Health Organization (世界卫生组织).

    5% of adults do not get enough exercise, according to the study. This number hasn't changed from 2001. Because of this, about 1.4 billion people are close to deadly diseases (疾病) such as heart disease and cancer (癌症).

    People should do at least 2 and a half hours of "moderate intensity (中等强度)" exercise each week, such as dancing or swimming. They can also do 75 minutes of "vigorous intensity (高强度)" exercise, such as running or playing soccer, according to the WHO.

    As for how to exercise more, experts says that we don't have to go to the gym (健身房) every time For example, we can go up and down stairs (楼梯) a lot instead of taking the lift. If we can't go to a dancing class each week, standing on one leg for 30 seconds a day is very good too.

    The study also found that women are less active than men, 32% of women hardly ever take exercise, compared to (比较) 23% of men. Women spend more time at home taking care of children and doing housework.

    But unlike that in most other countries, men are less active than women in China, with 16.6% of men and 12% of women not getting enough exercise.

Playing with apps on smart phones is very common among young people. Let's try some special apps and enjoy them.

How to learn English

How can you learn English well? Here are my suggestions. 

……

I hope these suggestions can help you.