Q: Read the following article and select the best answer. Article: A blue hole is a flooded sea cave with a hole that opens up at the land's surface. These cave systems form in carbonate rock, often on islands. Some blue holes have very special rock formations and water chemistry. Far below sea level, they contain some of the harshest environments on Earth, with no oxygen and no light. Yet these areas are filled with life forms that have adapted to the extreme conditions. Information gathered from these blue holes is helping scientists to increase their understanding of biology, archaeology and geology. But exploring these blue hole environments brings danger as well as discovery. Blue holes get their name from the color1 some have when seen from the air. The color1 is usually a reflection of the sky on the water. But not all of these cave systems have blue surfaces. Some contain dark or muddy water. Blue holes are the result of erosion in which water breaks down rock. Rain falling thousands of years ago contained chemicals which slowly wore away at the limestone landmass. These holes were later filled with sea water as the sea level changed. The rising and falling of sea levels and the mixture of salt and fresh water further wore away at these cave formations. Blue holes are vertical caves. But they can also have horizontal cave formations that may be hundreds of meters long. These flooded cave systems can be found in the ocean, or they can be found inland. Ocean caves are affected by tides, so they always have water movement. But blue holes on land are very still. They have several layers of water, chemicals, and bacteria. The top layer of fresh water comes from rainfall. This layer acts like a cap on top of the layered mixture, and keeps out oxygen from the atmosphere. The fresh water floats on a denser layer of saltwater. Underneath this is a layer of poisonous hydrogen sulfide, produced by bacteria living in the water. Underneath this layer is anoxic seawater -- water that does not contain any oxygen. Underwater caves are probably one of the least explored ecosystems... Question: According to the Passage, blue holes _ . - are now a popular choice for tourists - are flooded caves found mostly on islands - have appeared as rocks pile up year by year - can give off bright blue light deep in the caves
A: are flooded caves found mostly on islands

Q: Read the following article and select the best answer. Article: As societies develop, their members start to see things not so much according to what they need, but according to what they want. When people have enough money, these wants become demands. Now, it' s important for the managers in a company to understand what their customers want if they are going to develop effective marketing strategies . There are various ways of doing this. One way at supermarkets, for example, is to interview customers while they're doing their shopping. They can be asked what they prefer to buy and then the results of the research can be studied. This provides information on which to base future marketing strategies. It' s also quite normal for top managers from department stores to spend a day or two each month visiting stores and mixing freely with the public, as if they were ordinary customers, to get an idea of how customers act. Another way to get information from customers is to give them something. For example, some fast food restaurants give away tickets in magazines or on the street that permit customers to get part of their meal for nothing. As well as being a good way of attracting customers into the restaurants to spend their money, it also allows the managers to get a feel for where to attract customers and which age-groups to attract. Another strategy used at some well-known parks such as Disneyland is for top managers to spend at least one day in their work, touring the park dressed as Mickey Mouse or something like that. This provides them with a perfect chance to examine the scene and watch the customers without being noticed. Question: The main idea of the text is _ . - how to find out customers' social needs - how to develop marketing strategies - how to do market research - how to encourage customers to spend more money
A: how to do market research

Q: Read the following article and select the best answer. Article: Air pollution, such as haze, has become a serious problem around the world. Besides wearing a mask, what else can we do to protect ourselves from the dirty air? Scientists have developed a new inhaler that can reduce the effect air pollution has on people. It could help millions of people who are suffering from air pollution,the Guardianreports. This inhaler is developed by German company Bitop and contains a molecule named Ectoine. The molecule creates a layer that protects lungs from polluted air. It's reported that the inhaler will be affordable to most people when it comes to the market. Air pollution kills more than three million people a year worldwide and leads to health problems like lung and heart disease and strokes, according to a 2016 research project in the journalNature. It is also linked to brain disease, mental illness and diabetes . Andreas Bilstein at Bitop believed that the inhaler could be useful around the world, because air pollution is not just a European problem: "Especially in Asia - China in particular - the demand for such a product is even higher." Many Chinese cities have been suffering from haze. According to World Health Organization, two of the 10 most polluted cities in the world in 2015 were in China. About 800,000 deaths that are linked to air pollution take place in the country every year. However, such inhalers should never be an excuse for not trying to stop air pollution, said Professor Jean Krutmann at the Leibniz Research Institute for Environmental Medicine. "The best thing is that we have clean air and we don't need any prophylactic treatment," he said. Question: Which of the following is NOT true? - Air pollution kills millions of people a year worldwide. - Air pollution can cause mental illness. - There are no air pollution problems in Europe. - Air pollution is a serious problem in China.
A: There are no air pollution problems in Europe.

Q: Read the following article and select the best answer. Article: As more women in the United States move up the professional ladder, more are finding it necessary to made business trips alone. If you are married, it is a good idea to encourage your husband and children to learn to cook a few simple meals while you are away. They will be much happier and probably they will enjoy the experience. If you will be eating alone a good deal, choose good restaurants. In the end, they will be much better for your digestion. You may also find it useful to call the restaurant in advance and tell them that you will be eating alone. Finally, and most importantly, prepare your travel needs as a businesswoman; this starts with lightweight luggage which you can easily manage even when fully packed. Take a folding case inside your suitcase; it will come in extremely handy for dirty clothes, as well as for business papers you no longer need on the trip. And make sure you have a briefcase so that you can keep required papers separate. Obviously, experience helps, but you can make things easier on yourself from the first by careful planning, so that right from the start you really can have a good trip! Question: It can be inferred from the passage that _ - a greater percentage of women are advancing professionally in the US than in the past - professional men refuse to go on business trips with women - businesswomen become successful by showing a willingness to travel alone - husbands are encouraged to learn to cook while their wives go on business trips
A: a greater percentage of women are advancing professionally in the US than in the past