----- Nội dung dịch tự động từ ảnh ----- Exercise 4. Read and complete each numbered blank in the passage with the correct answer A, B, C, or D. Thousands of years before the invention of the Internet, people entertained (1) the sky at night and connecting the stars to create pictures of animals, objects, and legendary heroes. These by gazing into ancient stargazers noticed that some shining stars just followed their own paths across the (2) The ancient Greeks called them "planetes", meaning wanderers. sky. What exactly is a planet? It sounds like an extremely (3) question. However, there have been for a lot of debates in the scientific world until recently. In 2006, scientists came up with three (4) planethood. A planet must orbit the sun; it must be large enough so that its own gravity makes it into a spherical shape, and it must have an orbit free of other small objects. Pluto, which was once considered the "ninth planet" in the solar system, (5) to meet the third condition. Therefore, it was downgraded into a dwarf planet. 1. A. others B. someone C. themselves 2. A. night B. bright C. blue 3. A. promising B. difficult C. debatable D. neighbours D. day D. easy 4. A. types B. conditions C. ideas 5. A. strived B. wanted C. failed D. grades D. managed