Read the article and select the best answer. Article: If you look at the night sky, you'll often see stars moving very quickly. In fact, they move much more quickly than they should according to their size and the laws of physics. Scientists do not completely understand why the speed of these stars is so high. But many believe the reason is that much of the universe is made of something called "dark matter". Groups of stars called galaxies, such as the Milky Way, might even be made up of 90 percent dark matter. How much something weighs depends on where it is. The same object weighs only half as much on Mars as it does on Earth and almost three times as much on Jupiter. So scientists prefer to talk about the mass of something rather than how much it weighs, because mass does not change. They can work out the mass of galaxies by measuring the distance between them and the speed they move at. Recently, Jorge Penarrubia, a senior academic at Edinburgh University, UK, and his team discovered something interesting: The mass of the Milky Way is only half as much as the mass of another nearby galaxy, Andromeda. This seems strange, and dark matter may explain why. Finding out more about dark matter could help us understand how the universe began, but this is not easy. Lots of scientists with different types of expert knowledge are working on the problem. We can't see dark matter, it's very difficult to measure and we can't find out its mass. Unlike stars, dark matter doesn't produce or reflect light. But we can make a good guess that it is there because of the way things move and the way light bends. Experts now think dark matter may be very different from the matter that we find on Earth. There may also be five times as much dark matter in the universe as ordinary matter. Question: Dark matter is difficult to investigate because _ . Options: A: it travels at a very fast speed B: we can't see where it is or measure its mass C: it's hard to measure the light it produces and reflects D: it is much bigger than ordinary matter in size
B

Read the article and select the best answer. Article: Yesterday I started the Year of Giving, my first day of a year-long journey into exploring the act of giving and the meaning of charity. I chose December 15 as the starting date, which marked three years since my mother died from heart disease. She was one of the most generous people that I have ever known. She always thought of others first and certainly serves as an inspiration to me. I had a rather busy day yesterday, ironic for someone who is unemployed right now. In the morning I went to the gym, and unsuccessfully got the phone call from the unemployment office for some job searching. Before I knew it, it was noon. I grabbed a quick lunch and rushed down to a meeting. On my way to Connecticut, I wondered if I would see someone that I would feel forced to give my first $10 to. I was running late and decided to do it afterwards. After the meeting I had about half an hour to find the first person of my Year of Giving! I decided to check out Dupont Circle. I had met a guy there named Jerry once and thought he would willingly accept my first $10. He wasn't there, but I did see a man sitting by himself who looked really lonely, so I approached him. Now I had to figure out what I was going to say. I think I said something like, "Hi, can I sit down here?" "I would like to know if I could give you $10?" He asked me to repeat what I had said. I did, then he looked at me funny, got up and left. I then started walking south where I spotted a man standing by the bus stop on Connecticut Ave. He appeared to be in his 60s. I don't know what drew me to him, but I thought I would make my second attempt. I was a bit nervous and asked him which bus came by that stop. Then I explained that I was starting a year-long project to give $10 to someone every day and that I wanted to give my $10 for today to him. The gentleman, I later found out that his name was Ed, responded without hesitation that he could not accept my offer and that there were many people more deserving the money than him. This was exactly one of the things... Question: The author set the starting date on December 15 to _ . Options: A: help the charity B: remember his mother C: make an exploration D: fulfill a wish of his mum
B

Read the article and select the best answer. Article: Food sometimes gets poisoned with harmful things. A person who eats such food can get an illness called food poisoning . Food poisoning is usually not serious, but some types are deadly. The symptoms of food poisoning usually begin within hours of eating the poisoned food. Fever is one of the most common symptoms. Certain microorganisms cause most types of food poisoning. Bacteria and other microorganisms can poison eggs, meat, vegetables, and many other foods. After entering the body, these tiny living things release poisons that make people sick. Some chemicals can also cause food poisoning. They are often added to food while it is being grown, processed, or prepared. For example, many farmers spray chemicals on crops to kill weeds and insects. Some people may have a bad reaction to those chemicals when they eat the crops. Some plants and animals contain natural poisons that are harmful to people. These include certain kinds of seafood, grains, nuts, seeds, beans, and mushrooms. When people handle food properly, the risk of food poisoning is very small. Microorganisms multiply rapidly in dirty places and in warm temperatures. This means that people should never touch food with dirty hands or put food on unwashed surfaces. Food should be kept in a refrigerator to stop microorganisms from growing. Meat needs to be cooked thoroughly to kill any dangerous microorganisms. People should also wash food covered with chemicals before eating it. Finally, people should not eat wild mushrooms or other foods that grow in the wild. Some of these foods may contain natural materials that are poisonous to humans. In addition, some types of fish can be poisonous. Most people recover from food poisoning after a few days of resting and drinking extra water. If people eat natural poisons, they must go to the hospital right away to have their stomachs emptied. Question: Which of the following statements is NOT true? Options: A: Food when poisoned can make people sick. B: Food poisoning means death. C: Food poisoning comes in varieties. D: Food poisoning can be serious.
B