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yennhi122003
2 năm trước
(x+1)+(x+2)+(x+3)+.....+(x+98)+(x+99)=5049
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III. Choose the item A, B, C or D that best answers the question about the passage. A UFO (Unidentified Flying Object) is any object flying in the sky which cannot be identified by the person who sees it. Sometimes the object is investigated. If people cannot figure out what the object is after an investigation, it is called a UFO. If they figure out what the object is, it can no longer be called a UFO because it has been identified. Even though UFOs can be anything, people can use the world UFO when they are talking about alien spacecraft. Flying saucer is another word that is often used to describe an identified flying object. Studies estimate that 50-90% of all reported sightings are identified later. Usually 10-20% are never identified. Studies also show that very few UFO sightings are hoaxes (people trying to trick other people). Most UFOs are actually natural or man-made objects that looked strange. 80-90% of UFOs are identified as one of three different things: (a) astronomical causes (for example: planets, stars, or meteors); (b) aircraft; and (c) balloons. 10-20% of UFOs are other causes, such as birds, clouds, mirages, searchlights, etc. 1. Another word used to describe a UFO is . A. flying saucer B. cooking plane C. spacecraft D. astronaut 2. How many percent of all reported sights are not identified? A. 20-30% B. 10-20% C. 30-50% D. 80-90% 3. Most of UFOs are identified as one of the following things except . A. balloons B. clouds C. stars D. rains 4. Which of the following sentences is NOT true? A. UFO means Unidentified Flying Object. B. Many UFO sightings are hoaxes. C. UFO is often used to talk about alien objects. D. Over half of all reported UFO sightings are identified. 5. What does the word “figure out” in paragraph 1 mean? A. calculate B. observe C. explain D. require

I. Choose the words given to fill in the blanks correctly. light between becomes month around seems see earth Once a month, the moon travels in a complete circle (1) the earth. As it moves in its circle, it (2) to change shape. This is because we, on Earth, (3) only that section of the moon that catches the sun’s light. When the sun, the moon and the earth are in a straight line with the moon in the middle, it is impossible for us to see the moon. At this point, the moon is said to be new. We are unable to see it in this position because the side facing the (4) is in shadow. As the new moon begins to circle the earth, however, we begin to see that part of its surface that catches the sun’s (5) . After some days, when it reaches the position where the earth is (6) the sun and the moon, we see the full moon. Later, it again (7) half moon, becoming smaller and smaller until it disappears again to become the new moon. This cycle takes 28 days or a lunar (8) . II. Choose the word or phrase among A, B, C or D that best fits the blank space in the following passage. Why does Man want to go to other planets (1) the solar system? Just for adventure? True, (2) is adventure in space travel. But a (3) to other planets would also be (4) . For example, space stations could be built that would give us (5) information about the weather. In space stations (6) around the earth, Man could live and study the cloud formation on (7) surface. These formations could tell us what weather to (8) in any part of the world at any time. (9) information would be useful to pilots, to ship captains, and even to farmers (10) must set dates for planting and harvesting. 1. A. in B. on C. at D. of 2. A. this B. there C. that D. it 3. A. travel B. fly C. trip D. drive 4. A. practice B. practiced C. practicing D. practical 5. A. valuable B. wealthy C. expensive D. amused 6. A. moves B. moving C. moved D. moveable 7. A. his B. her C. its D. their 8. A. hope B. believe C. consider D. expect 9. A. Such B. Those C. So D. These 10. A. which B. who C. whom D. whose

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