Steel, concrete(混凝土) and glass are the usual materials in any skyscraper. But more high buildings are now using wood.

    In the last four years, Australia, Norway, England and Canada have all built wooden skyscrapers. The latest one is in Sweden, a new, 19-storey wooden hotel called "Sida vid Sida" (Side by Side).

    Why are wooden skyscrapers being chosen ahead of concrete ones? Let's find out.

    Is it strong enough?

    Wood has been used in many Chinese buildings for thousands of years, but is it strong enough for skyscrapers?

    "There's a lot of new materials made out of wood that are able to build big buildings," material expert Dr Michael Ramage told CNN when he was interviewed.

Architects (建筑师)have done thousands of experiment to make sure it is. They place layers of wood across one another coated with special glue to create very strong material.

Wood also lasts a long time and doesn't break down if it is well looked after. The examples include the rooftops of Beijing's Forbidden City and some 700-year-old houses in England.

Ramage also said on the internet that bamboo could be cut in special ways to make it even stronger than normal wood.

    Won't it catch fire?

    Wooden buildings sound dangerous when it comes to fire. But experts say they may be safer than concrete ones if there is a fire.

    "Wood doesn't burn in the way the public imagines," Ramage said. Very small pieces of wood catch fire easily, but very big pieces of wood are quite hard to set on fire, he said.

    Imagine a perfect day: the weather is good and everything seems fine. When, suddenly, your mobile phone loses its signal, the television has no programs, and you can't get online with your computer.

    What has happened? These are just the types of problems a solar storm（太阳风暴）might cause. You may not think of storms as putting our society in danger. But today, a solar storm is as serious as other bad events, such as earthquakes.

    A solar storm is caused by solar flares（太阳耀斑）: large explosions（爆炸）near the sun that can give off lots of energy. The strong energy can stop the satellite systems（卫星系统）that control our computers, telecom networks and so on. These storms can even cause the power to go out for weeks or months.

    In the past few months, scientists have recorded some of the strongest sun flares in years. The most recent one happened around Valentine's Day, 2011. It caused radio and satellite signals to go down in some northern cities in China.

    “Solar flare activity is going to be much worse than what we've seen in the past. We're not talking about a few cities losing power, it could be half of the country, maybe more.” SolarStormWarning.com, a US website about space weather, warned.

    Scientists say that little can be done to predict such a storm. Governments around the world are trying to work together before the next storm, although they are not sure when that may happen.

    Thanks to software like Apple's Siri or Microsoft's Cortana, it's easier than ever to do something on our phone or computer. All we have to do is "talk", and our favorite song starts playing a few seconds later. But in the neat" future, asking our phone to play a song by using our voice will seem as old--fashioned. That's because US tech company Microsoft recently applied for a patent* for a "brain control interface"(BCI): meaning that soon, we may be able to control our phone and computer with our thoughts.

    BCI technology works by changing brain signals into computer commands. This technology isn't brand new, however. Last year, for example, it was reported that scientists were able to help a disabled man from the US, 53-year-old Bill Kochevar, to move again. To do this, Kochevar was fitted with BCI technology, as well as equipment to make his muscles move. After a few weeks of getting used to it, Kochevar was able to use his thoughts to "tell" the BCI to move his muscles, meaning he was able to feed himself for the first time in years.

    Apart from helping disabled people, it's hoped that BCI technology will improve the daily lives of other people too. US social networking platform Facebook announced last year that it was working off BCI technology to help people type by using their brain. By 2020, the company hopes to have created a system that will allow people to type up to 100 words per minute just by thinking about them.

    However, many people are worried that technology that tan read our thoughts will create privacy problems, especially if social media companies are included. But Facebook researcher Regina Dugan said at a meeting last year that the company has no interest in reading people's private thoughts. "That might be more than any of us care to "know. And it's not something any of us should have a right to know," she said.

    A zero-waste life is a lifestyle that hardly creates any rubbish. So, a zero-waste store is about providing a kind of everyday and pleasant-looking zero-waste products to help people start on a zero-waste life journey.

    "Zero waste" or "danshari" was first suggested by a French woman called Bea Johnson. Her idea is: live a life and try not to create any rubbish; use different kinds of ways to save the environment such as stopping the use of one-off objects; giving unwanted things to others or giving them away to organizations like the Red Cross.

    Yu Yuan, 27, is deeply interested in this idea. She and her boyfriend have lived in Beijing for many years. And earlier she used to buy things without thinking about them carefully until she saw a video about "zero waste", in which a family of four placed the rubbish they produced every year in a jar (罐). After watching the video, Yu wanted to experience this zero-waste lifestyle with her boyfriend.

    A zero-waste life follows the 6R rule-Refuse Reduce, Reuse, Repair, Recycle and Rot. Over August-October when Yu followed the rule of zero waste 6R, she and her boyfriend Joe Harvey both produced only two cans of rubbish.

    Now, the couple have opened a small shop in Beijing, where they use wood products to take the place of plastic ones and cloth bags printed with environmentally friendly logos. Most products sold in the store can be reused. The store also has second-hand books and CDs/DVDs with, ideas to make the best of the used things.

    "Those who once experienced the non-waste lifestyle have slowly changed their ideas," says Ya, "The zero-waste lifestyle is not for ascetics (苦行僧). It is just around us at our finger-tips." Yu expects some of her friends to join her on the road to zero waste.