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Read the following passage and mark the letter A, B, C, or D to indicate the answer to each of the question. Called the ‘Red Planet,’ Mars is roughly half the size of Earth, and one of our closest neighboring planets. Though Mars is the most Earth-like of any other planet, the two are still worlds apart. Living on Mars has been the stuff of science fiction for decades. However, can humans really live on Mars? Will it ever be possible or safe? NASA (the National Aeronautics and Space Administration) hopes to find out. NASA researchers on Earth are conducting several experiments together with the International Space Station (ISS) to study the health and safety issues that may tell us if life on Mars is possible. Food and oxygen would be the main necessities for travelers living extended periods on Mars. The need to grow plants, which provide both food and oxygen, would be a key. But the decreased gravity and low atmospheric pressure environment of the planet will stress the plants and make them hard to grow. However, space station crews are growing plants in controlled environments in two of the station’s greenhouses. They take care of the plants, photograph them, and collect samples to be sent back to Earth. Researchers then use the data to develop new techniques that will make it possible to grow plants successfully in space. Another concern for space travelers is the health hazards posed by the effect of space radiation on humans. A spacecraft traveling to Mars would be exposed to large amounts of radiation. Since human exposure to such intense radiation would mean certain death, the spacecraft used for such travel would have to protect the humans on the inside of the craft from exposure. Researchers are using special machines inside the crew areas of the International Space Station to carefully watch radiation levels. NASA scientists, who have maintained radiation data since the beginning of human space flight, continue to learn about the dangers it poses. Researchers use the station to test materials that could be used in making a spacecraft that could successfully travel to Mars. Will it ever be safe for humans to live on Mars? It is still too early to say. But thanks to the dedicated researchers of NASA and the results of ISS experiments, we are getting closer to knowing every day.                    (Adapted from “Select Readings –Intermediate Tests” by Linda Lee and Erik Gundersen) What does the passage mainly discuss?

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Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each the numbered blanks. Sir Isaac Newton, the English scientist and mathematician, was one of the most important figures of the 17th century scientific revolution. One of his greatest achievement was the (26) _______ of the three laws of motion, which are still used today. But he also had a very unusual personality. Some people would say he was actually insane. His father died before he was born, and his mother soon remarried. The young Isaac hated his stepfather so much that he once (27) _______ to burn his house down - when his stepfather and mother were still inside! Fortunately he did not, and he went on to graduate from Cambridge without being thrown into prison. Isaac's first published work was a theory of light and color. When another scientist wrote a paper criticizing this theory, Isaac flew into an uncontrollable rage. The scientist responsible for the criticism was a man called Robert Hooke. He was head of the Royal Society, and one of the most respected scientists in the country. (28) _______, this made no difference to Isaac, (29) _______ refused to speak to him for over a year. The simple fact was that Isaac found it impossible to have a calm discussion with anyone. As soon as someone said something that he disagreed with, he would lose his temper. For this reason he lived a large part of his life isolated from (30) _______ scientists. It is unlikely that many of them complained.                                                              (Source: https://www.biography.com/scientist/isaac-newton)

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