Questões de Vestibular de Inglês

    As we all know, electricity is a fundamental need. On a daily basis, we consume electricity even without us knowing it. Just a simple task such as listening to your music player consumes electricity. Today, most of our electric generators and power plants are fed with fossil fuels such as petroleum and coal. However, due to the exponential increase of power demand, fossil fuel supplies are slowly being depleted. Not only that, but also burning fossil fuels has given off greenhouse gases and other unwanted byproducts. Because of this, the search for alternative energy sources is now a necessity. One of the most promising alternative energy sources today is Wind Powered Generators. So, what is a wind-powered generator? Basically it is the use of wind as a mechanical force needed to power an electric generator. Utilizing wind as an energy source is not exactly a new idea. The ancient Persians were the first to use wind to pump water, cut wood, and grind food and others by building windmills. Even today you can find windmills still being used on some farms. It was the use of wind as an electric source that came into existence much later. The first practical wind powered generators were built in 1970, but yet we rarely see them in widespread use today, why? Let’s look at the advantages and disadvantages of the wind powered generator.

    The main advantage of wind powered generators is that they have, ideally, zero gas emissions – unlike fossil-fueled power generators. Because of the alarming effects of greenhouse gases and global warming, we want our power generators to be as clean and as environmentally friendly as possible. Since there is no burning process in a wind powered generator that produces toxic gases, it is very safe to build one in residential areas. Also, with proper engineering and enough wind, these generators can provide a high rate of wattage that can go as high as the Megawatt range. Another advantage is that it can be implemented using several small turbines connected together. This is a good thing when there is not enough space for huge structures.

     The major disadvantage of wind powered generators is that wind power varies greatly from one place to another and from day to day and season to season. Sometimes wind may be strong enough to supply energy, but that strength cannot be maintained due to changes in weather patterns. Needing strong, constant wind to most effectively power wind generators is one reason they are often built in coastal areas. Another disadvantage is that the structure of most practical wind powered generators is huge and bulky. Commonly, its size is proportional to the wind power it can collect.

    Research in wind power has now intensified because of its innate advantages over other power generators. With this increase in interest in wind energy and alternative energy sources as a whole, our future will become brighter and more and more remote areas will eventually enjoy the benefits of clean electric energy. In an electricity-dependent world, power supplies must provide the required electricity for communities and businesses. Wind powered generators might just be the solution for power shortages.

Disponível em: http://mysolarcellhome.org/articles/pros-and-cons-of-wind-powered-generators. 

    Don’t go overboard with the SPF. The American Academy of Dermatology recommends using an SPF of at least 30, but most experts agree to not go over 50. It’s not that a higher SPF doesn’t provide any more protection, but once you get above 50, that increase is negligible. Case in point: SPF 50 blocks about 97% of UVB rays, while SPF 100 blocks about 99%.

    But most sunscreen users don’t think about that; rather, they see a number that’s twice as high and assume they’ll get twice as much protection or that the protection will last twice as long, which cultivates a false sense of security that could lead to a bad burn. “SPF values above 50 are really misleading,” Lunder says. “They offer a very small increase in sunburn [UVB] protection, and they don't offer better UVA protection.” She says that the FDA is considering a rule to cap SPF values at 50, but nothing has been finalized.

    And then there’s the fact that, although the increase in SPF doesn’t add much protection, it could increase your chances of negative side effects from the ingredients. “We do not recommend SPF of 50 or higher, as the minimal added protection does not outweigh the exponentially more active ingredients required to do so,” Chris Birchby, the founder of the sun-care line Coola, tells Teen Vogue. “More active ingredients increase the chances of skin irritation.”

Not Long Ago people believed that in the future we would work less, have more free time, and be more relaxed. But sadly this has not happened. Today we work harder, work longer hours, and are more stressed than ten years ago. We walk faster, talk faster, and sleep less than previous generations. And although we are obsessed with machines which save us time, we have less free time than our parents and grandparents had. But what is this doing to our health? An American journalist James Gleick in a new book, Faster: the Acceleration of just about everything, says that people who live in cities are suffering from 'hurry sickness'- we are always trying to do more things in less time. As a result, our lives are more stressful. He says that if we don't slow down, we won't live as long as our parents. For most people, faster doesn't mean better.

Newspaper articles today are shorter and the headlines are bigger. Most people don't have enough time to read the articles, they only read the headlines! On TV and the radio, newsreaders speak more quickly than ten years ago.

In the USA there is a book called One-Minute Bedtime Stories for children. These are shorter versions of traditional stories, specially written for 'busy parents' who want to save time!

Some answerphones now have 'quick playback' buttons so that we can re-play people's messages faster – we can't waste time listening to people speaking at normal speed!

Even when we relax we do everything more quickly. Ten years ago when people went to art galleries they spent ten seconds looking at each picture. Today they spend just three seconds!

In the USA the national sport, baseball, is not as popular as before because it is a slow game and matches take a long time. Nowadays many people prefer faster and more dynamic sports like basketball.

The only thing that is slower than before is the way we drive. Our cars are faster but the traffic is worse so we drive more slowly. We spend more time sitting in our cars, feeling stressed because we are worried that we won't arrive on time. Experts predict that in ten years' time the average speed on the road in cities will be 17 km/h.