Danh sách câu hỏi
Có 26157 câu hỏi trên 524 trang
Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions.
The coming decades will witness considerable changes in the way energy is supplied and utilized. In some major oil-producing nations "peak oil" has already been reached, and they are unable to manufacture so much oil as in the past. Consequently, many countries are focusing on the switch to a low carbon economy considering global warming as well. This transition will lead to major changes in the supply and use of electricity. To meet these challenges, countries are investing in Smart Grid technology.
Smart Grid technology basically involves the application of a computer system to the electricity network. The computer system can be used to collect information about supply and demand. With better information about electricity demand, the network will be able to increase the amount of electricity delivered per unit generated, leading to potential reductions in fuel needs and carbon emissions.
Smart Grid technology brings benefits to the consumer too. They will be able to collect real-time information on their energy use. Varying tariffs throughout the day will give customers the incentive to use appliances at times when supply greatly exceeds demand, leading to great reductions in bills. Smart meters can also be connected to the internet or telephone system, allowing customers to switch appliances on or off remotely.
However, we are facing a range of challenges related to these changes. The first involves managing the supply and demand. Sources of renewable energy such as wind, wave and solar are notoriously unpredictable, and nuclear power, which is also set to increase as nations switch to alternative energy sources is inflexible. With oil and gas, it is relatively simple to increase the supply of energy to match the increasing demand during peak times of the day or year. With alternative sources, this is far more difficult, and may lead to blackouts or system collapse. Potential solutions include investigating new and efficient ways to store energy and encouraging consumers to use electricity at off-peak times.
Another problem is that a number of renewable power generation sources are located in remote areas, such as windy uplands and coastal regions, where there is a lack of electrical infrastructure. New infrastructures therefore must be built. Thankfully, with improved smart technology, this can be done more efficiently by reducing the reinforcement or construction costs.
Though Smart Technology is still in its infancy, pilot schemes to promote and test it are already underway. Consumers are currently testing the new smart meters which can be used in their homes to manage electricity use. There are also a number of demonstrations being planned to show how the smart technology could practically work and trials are in place to test the new electrical infrastructure. Cities are prime candidates for investment into smart energy, due to the high population density and high energy use it is here where Smart Technology is likely to be promoted first utilising a range of sustainable power sources, transport solutions and an infrastructure for charging electrically powered vehicles. The infrastructure is already changing fast. By the year 2050, changes in the energy supply will have transformed our homes, our roads and our behavior.
According to paragraph 1, what has happened in some oil producing countries?
Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions.
Robots are useful for exploring and working in space. In particular, many robots have been sent to explore Mars. Such robots have usually looked like a box with wheels. Though these robots are useful, by their very nature they are unreliable, extremely expensive, and they break easily. Also, they cannot do many tasks. Because of these problems, scientists have been developing a new and unusual kind of robot. These new robots move like snakes, so they have been given the name ‘snakebots’.
The way a snake is shaped lets it get into very small spaces, like cracks in rocks. It can also push its way below the ground or climb up different kinds of objects like high rocks and trees. Such abilities account for the usefulness of a robot designed like a snake. A snakebot would be able to do these things, too, making it much more effective than regular robots with wheels, which easily get stuck or fall over. Since they can carry tools, snakebots would be able to work in space, as well. They could, for example, help repair the International Space Station.
But how can such a robot shape be made? A snakebot is built like a chain made of about thirty parts, or modules. Each module is basically the same in that they all have a small computer and a wheel to aid movement. The large computer in the "head" of the snake makes all of the modules in a snakebot work together.
The modular design of the snakebot has many advantages. If one module fails, another can be added easily. Snakebot modules can also carry different kinds of tools, as well as cameras. Since each module is actually a robot in itself, one module can work apart from the rest if necessary. That is, all the modules can separate and move on their own, and then later, reconnect back into a larger robot. Researchers are also trying to develop snakebots made of a special kind of plastic that can change its shape using electricity, almost like animal muscles. Snakebots made with this plastic will be very strong and hard to break.
Overall, the snakebot design is much simpler than that of common robots. Thus, snakebots will be much less expensive to build. For example, a robot recently sent to Mars cost over a hundred million dollars, whereas snakebots can cost as little as a few hundred dollars. With their versatility and affordability, snakebots seem to be the wave of the future, at least as far as space robots are concerned.
What is the focus of this reading?
Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each of the numbered blanks.
People all around the world are more and more associated with social networking, (5) _____ is a useful tool for those in the digital era. Social networking aims at promoting and aiding communication. (6) _____, this type of technology may be doing more (7) _____ than good. It is not only changing how we communicate, but how we associate with each other in everyday life. Sarah Zay, of USA Today, expressed that “With the growth of websites such as Facebook, social networking may be (8) _____ of replacing traditional personal interactions for the future generation”. Traditional interactions will continue to be at risk if we don’t (9) _____ the impacts of our social media. Social networking affects our lives in many ways, including our communication, self-expression, bullying, isolations, companionships, and even our very own sense of humanity.
People all around the world are more and more associated with social networking, (5) _____ is a useful tool for those in the digital era
