Với giá trị nào của `k` thì hàm số sau đây đồng biến? nghịch biến? `y = (k^2 – 9)x + 4`

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VI. Choose the correct answer A, B, C or D to complete the following passage. NASA announced plans that are out of this world - literally! The space agency hopes to (26) _____ humans to the moon again by 2020. NASA hopes to make a giant leap - back to the moon. Back in 2005, the U.S. space agency announced its plan to send four astronauts to the moon (27) _____ the next 15 years. NASA officials say the moon is just the first step. They hope future missions will take astronauts to Mars and beyond. “We will return to the moon no later than 2020 and extend the human presence across the (28) _____ system and beyond,” says Michael Griffin, the head of NASA. So far, the moon is the only place beyond Earth that humans have visited. At 226,000 miles away, the moon is Earth's (29) _______ space neighbour. On July 20th, 1969, Neil Armstrong and Edwin “Buzz” Aldrin became the first astronauts to land on the moon. They traveled there aboard Apollo 11. When Armstrong first set foot on the moon, he spoke these famous words: “That's one small step for a man, one giant leap for mankind.” During NASA's Apollo program, 12 American astronauts explored the lunar terrain. The last U.S. trip to the moon (30) ______ in December 1972. 26. A. send B. sending C. sent D. have sent 27. A. for B. at C. on D. within 28. A. science B. planet C. solar D. life 29. A. closest B. closer C. closely D. as close as 30. A. finished B. had finished C. finishes D. will be finishing VII. Read the following passage about tornadoes and choose the best answer. Tornadoes Did you ever see the movie The Wizard of Oz? A tornado sweeps up Dorothy and Toto, sending them to a new world where there are witches and talking lions! That entire story is fiction, but tornadoes are real and they are serious business. In fact, they can be the most dangerous storms of all. Tornadoes are sometimes referred to as twisters or cyclones. They are shaped like a cylinder. They are born in thunderclouds. The winds inside a tornado swirl around and around and can be more than 300 miles per hour (mph). The winds are so strong that tornadoes can lift animals, cars, and even houses. The United States has more tornadoes than any other country in the world. States such as Texas, Oklahoma, Kansas, and Nebraska are hit hard by tornadoes. This part of the country is known as “Tornado Alley.” Tornado season is during the springtime and summer. If the conditions are right, a tornado can happen any time of year. 31. Where do tornadoes begin? A. in the ocean B. underground C. in cyclones D. in thunderclouds 32. Why does the author mention The Wizard of Oz at the beginning of the passage? A. To give a famous example of a tornado. B. To give a history of tornadoes. C. To show that hurricanes are not real. D. To explain why tornadoes are dangerous. 33. Based on the passage, people who live in Tornado Alley should ___________. A. expect tornadoes only during the summer. B. be very familiar with the movie The Wizard of Oz. C. be prepared for the dangers of tornadoes. D. think about moving to the United States. 34. The word conditions in the last paragraph means ___________. A. preparations B. dangerous hazards C. the way things are D. lucky feelings 35. What is the main idea of this passage? A. Some states get tornadoes more than other states. B. Tornadoes are dangerous storms that affect the U.S. C. Tornadoes are different from how they are in movies. D. Many tornadoes do not cause a lot of damage. VIII. Rewrite the sentences using the word given in brackets. 36. I can't understand him because he speaks so quickly. => If ________________________________________ 37. You had better not lend him any more money, Amanda" said John. => John advised Amanda ________________________ 38. Many natural disasters have been caused by global warming. => Global warming _____________________________ 39. Talking to your family members every day is very important. => It is ___________________________________________ Question 40. “Is your uncle working as a pilot for NASA?” Julia asked me. => Julia asked _____________________________________