2020-2021学年牛津上海版高中二年级第一学期Unit 6 Space exploration reading课件

Our planet is getting ~er and ~er because/because of ____________. What if one day the earth is overcrowded like this? What if one day the earth is not fit for human beings to live on? Mars transform Why Mars? transformer polar ice cap polar a. pole n. Earth vs Mars 24 ½ hours 687 days no water, but a lot of ice -60℃ carbon dioxide(95%) 20kg 228 million km Length of one day 24 hours Length of one year 365 days Water? Yes Average temperature 150C Main gases Nitrogen78% Oxygen 21% Gravity: weight of a 60kg person 60kg Average distance from the Sun 150 million km * Paras1-3 A dream? When? Why? How? Prediction What conditions on Mars will scientists try to change? Stage 1 (AD2030-2045) What kind of work do people do at this stage? Construct underground buildings Conduct experiments Look for site for future landings Check for signs of life Construct v. to build n. construction a survey/ an inquiry/… Organize and do spacesuit Para. 5 (stage 2)