Question: Read the following article and select the best answer. Article: Scientists study the ocean in many different ways. Although many marine scientists focus on animals in the ocean, others seek to gain a better understanding of the ocean's chemical and physical components . Scientists are learning a great deal about the natural and human-caused processes that shape the ocean and its many life forms. Much of the present research focuses on how human activity influences the ocean. Clean water is a limited resource, and ocean pollution does harm to plant and animal health. Some scientists are now studying ocean water to find out just how contaminated it is. Scientists are also working on new methods to estimate the presence of poisons in the ocean, which will help them develop better techniques for cleaning up the water. Others look at how sea living things get used to poisons because poisonous sea life has an effect on humans too. For example, some seafood is poisoned, which may cause a threat to humans who eat it. Another type of marine scientist tries to learn more about the history of the ocean. Understanding the ocean's past tells scientists more about its patterns and cycles today and in the future. The ocean's past, which is recorded by deposits in the ocean floor, helps scientists understand such important matters as global climate change and other environmental differences. The more researchers learn about the history of the ocean and its relation to climatic and environmental changes, the more likely that they will one day understand what causes such changes. Other scientists are concerned with understanding how ocean systems work. The word systems refers to all the conditions and elements that are continually changing the ocean. Understanding these systems is necessary to protect the ocean and ensure the safety of its life forms. The cycles of ocean life also have an enormous effect on human life; for example, studying coastal waters is important because they provide much of the fish that humans eat. Marine geologists are earth scientists who work along the ocean... Question: Which of the following can best summarize the main idea of the passage? - Saving the ocean from destruction - Learning about the ocean - Finding out the history of the ocean - Researching the floor of the ocean
Answer: Learning about the ocean

Question: Read the following article and select the best answer. Article: Lisa was running late. Lisa, 25, had a lot to do at work,plus visitors on the way: her parents were coming in for Thanksgiving from her hometown. But as she hurried down the subway stairs, she started to feel uncomfortably warm. By the time she got to the platform, Lisa felt weak and tired-maybe it hadn't been a good idea to give blood the night before, she thought. She rested herself against a post close to the tracks. Several yards away, Frank, 43, and his girlfriend, Jennifer, found a spot close to where the front of the train would stop. They were deep in discussion about a house they were thinking of buying. But when he heard the scream, followed by someone yelling, "Oh, my God, she fell in!" Frank didn't hesitate. He jumped down to the tracks and ran some 40 feet toward the body lying on the rails. "No! Not you! " his girlfriend screamed after him. She was right to be alarmed. By the time Frank reached Lisa, he could feel the tracks shaking and see the light coming. The train was about 20 seconds from the station. It was hard to lift her. She was just out. But he managed to raise her the four feet to the platform so that bystanders could hold her by the arms and drag her away from the edge. That was where Lisa briefly regained consciousness, felt herself being pulled along the ground, and saw someone else holding her purse. Lisa thought she'd been robbed. A woman held her hand and a man gave his shirt to help stop the blood pouring from her head. And she tried to talk but she couldn't, and that was when she realized how much pain she was in. Police and fire officials soon arrived, and Frank told the story to an officer. Jennifer said her boyfriend was calm on their 40-minute train ride downtown-just as he had been seconds after the rescue, which made her think about her reaction at the time. "I saw the train coming and I was thinking he was going to die." she explained. Question: when did Lisa become conscious again? - when the train was leaving. - after she was back on the platform. - after the police and fire officials came. - when a man was cleaning the blood from her head.
Answer: after she was back on the platform.

Question: Read the following article and select the best answer. Article: What will power your house in the future? According to scientists at the Massachusetts Institute of Technology (MIT) in the US, it might be artificial leaves. Natural leaves can change sunlight and water into energy. It is known as photosynthesis . Now researchers have found a way to imitate this process. The artificial leaf developed by Daniel Nocera and his colleagues at MIT can be seen as a special silicon chip with catalysts . Similar to natural leaves, it can split water into hydrogen and oxygen when put into a bucket of water. The hydrogen and oxygen gases are then stored in a fuel cell, using those two materials to produce electricity, located either on top of a house or beside the house. Though the leaf is shaped like a poker card, scientists stated that it is promising to be an inexpensive somtoe of electricity in developing countries. "One can imagine villages in India and Africa not long from now purchasing an affordable basic power system based on this technology," said an American scientist, Docera. An artificial leaf is not a new idea. The first artificial leaf was invented in 1997 but too expensive and unstable for practical use. The new leaf, however, is made of cheap materials, easy to use and highly stable. In laboratory studies, Nocera showed that an artificial leaf could operate continuously for at least 45 hours. The wonderful improvements come from Nocera's recent discovery of several powerful new, inexpensive catalysts. These catalysts make the energy transformation inside the leaf more efficient with water and sunlight. Right now, the new leaf is about 10 times more effective at carrying out photosynthesis than a natural one. Besides, the device can run in whatever water is available. Hopefully, each home could possible have the access to the new application in the future. Question: The purpose of this article is to _ . - promote the new product - ask people to do the research - introduce a new kind of energy - show the process of photosynthesis
Answer:
introduce a new kind of energy