(课件)Unit 2 Out of This World 导读 话题妙切入-【提分教练】2023-2024学年新教材高中英语选择性必修第三册(译林版2020)

导读 话题妙切入 UNIT 2 Out of this world 1 导读 话题妙切入 2 导读 话题妙切入 3 导读 话题妙切入 4 导读 话题妙切入 5 导读 话题妙切入 6 导读 话题妙切入 7 They could see the size，colour，and brightness of a star． By the spectroscope． 导读 话题妙切入 8 谢谢观看 THANK YOU! 9 Space exploration is of great significance．Through space exploration，we human beings may uncover the unknown resources of the universe．It endows us with knowledge about the origin of life，with which we learn the dangers and make adventures in science and technology．Space exploration also provides a platform for nations to cooperate through participation in joint breakthrough．The space technology plays an indispensable role in our daily life，such as communication and transportation technology． Astronomy is the oldest science known to man．Thousands of years ago man looked at the stars and wondered about the heavens．But man was limited by the six planets that he could see with his eyes alone．The Greeks studied astronomy over 2，000 years ago．They could see the size，colour，and brightness of a star．They could see its place in the sky．They watched the stars move as the seasons changed．But the Greeks had no tools to help themselves study the heavens．Each new tool added to the field of astronomy helped man reach out into space．Until there were telescopes，man knew a little about the moon．They did not know that the planet called Saturn (土星) had rings around it．Their sight was so limited that they could not see all the planets．In the early 1700s，people thought there were only six planets．Neptune(海王星)，the last of eight planets to be discovered，was not seen until 1846． Before the spectroscope(分光镜)，man did not know what kind of gases was around the sun or other stars．Without the radiotelescope，we did not know that radio noises came from far in space．Today，astronomy is a growing science．We have learned more in the last fifty years than in the whole history of astronomy． [探究发现] 1．What could the ancient Greeks see 2，000 years ago when they observed the stars? ________________