In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.

Q: Article: The concept of solar power satellites, or SPS, first put forward in the 1960s, is still not widely known by the general public. For example, at many public exhibitions about energy, SPS is not even mentioned. This is mainly because very little money has been spent on SPS research There are people who claim that SPS is unrealistic - because launch costs are much too high today; or because it is too far away. So why do we believe that it is important to continue to do researches on SPS? The reason is very simple. Humans are going to need huge amounts of electric power in coming decades. Within 50 years the world population is expected to double, while economic growth will continue around the world, especially in the poorer countries. But existing energy sources already face serious problems. They are limited; they are polluted; they are dangerous. So 50 or 100 years from now, where is our power going to come from? Nobody knows. And so we believe that new large-scale possibilities should be studied further. We must remember that humans have some choices concerning our future. To some extent we can choose the direction in which our civilization develops. And choices that are made in the coming decades - such as the energy sources that we will or will not use, will have major, long-term meaning for human life on earth. We believe that if research continues to show that SPS is environmentally and economically attractive, SPS will open the door to a much more attractive future for human civilization than any ground-based energy source, and one that the public will support and that young people will find challenging and exciting. Furthermore energy from SPS can be readily used in developing countries, as the SPS 2000 project will show, thus aiding economic development worldwide. In addition, by creating large commercial fund for space engineering, SPS will open the frontier of space to economic development, thus creating a limitless new field for the growth of the world economy.
Answer: The Future Energy- SPS

A: Which of the following may be the best title for the passage?
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Q: Article: An earthquake is a trembling or shaking of the ground caused by the sudden release of energy stored in the rocks below the surface. Generally, earthquakes last only seconds. Strong ground shaking during a medium to large earthquake generally lasts about 10 to 30 seconds. Aftershocks can occur once in a while for weeks or even months. Many people think that there is an "earthquake season" or a kind of " earthquake weather ".As a matter of fact, there isn't. Earthquakes can occur at any time of the year and at time of day or night. Earthquakes occur under all weather conditions-sunny, wet. or cold without any special weather tendency . Also, you don't need to worry that the ground will open up and swallow people when earthquakes occur. Open ground cracks may form during an earthquake, for example, to land sliding or ground falling. However, such cracks tend to be open gaps (they don't " swallow") that a person could stand in afterwards. The safest place in an earthquake is an open field because buildings and falling objects can injure or kill you. If you are indoors, when you feel the ground start to shake, take cover immediately under a table or strong piece of furniture, placing something between falling objects and yourself. Don't " attempt to use the stairs or an elevator to get out of the building..
Answer: What usually injures people during an earthquake are falling buildings.

A: Which of the following is TRUE according to the passage?.
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Q: Article: Mexico City sits on an inland plateau surrounded by volcanic peaks, which makes air quality a constant concern for people who live here. In April, the country took a decisive step toward improving air quality by enacting a temporary ban on private and federal vehicles in the city. The rule forbids people from driving in the city one day each week and one Saturday each month. Electric vehicles, government service vehicles, public transport options and school buses are not included in the ban. Mexico City isn't the first urban centre to be involved in car-free living. But the ban is more than an awareness-raiser; it was enacted with the direct aim of solving air pollution. In March, the city sank into a deep brown haze of smog when pollution levels passed the 200 mark. The city ordered some 1.1m of the area's 4.7m cars off the streets and also offered free bus and subway rides. Mexico City's temporary vehicle ban raises questions about the best ways to improve urban air quality. India, whose citizens breathe some of the world's dirtiest air, has tried a variety of solutions. Earlier this year, the Indian government started a 4% sales tax on new-car purchases. Beijing also has experience with cleaning the air. The city introduced alternate-day rules in advance of the 2008 Olympic Games, which produced good, if short-lived, results. The day after the vehicle-use restrictions were _ , the blue faded back to gray. And then there is the London congestion charge, introduced in 2003. The charge has had a measurable effect on air quality. For now, Mexico City--named by the United Nations as the most polluted city on the planet in 1992--can look forward to the start of the region's rainy season, when daily showers will help to clean the air.
Answer: Its location.

A:
What makes the air quality of Mexico City a concern for citizens?
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