1. Spacecraft from the United States and from Russia have been to the moon, and men have walked upon its surface. Rock and soil samples and information of many other kinds have become available in recent years. Yet with all we know about the moon, there is even more that we dont know. 2. Following the end of the Apollo space program, the National Geographic Society published an excellent set of articles about the moon. Here, in shorter form, are some questions and answers from one of these articles. For the full story, see the September, 1973, issue of National Geographic. Were scientists right about what the moon would be like? 3. Many were, of course, but many were mistaken. One said there was no lava on the moon. Another said that the moon material would explode as soon as an astronauts boot touched it. One said there would certainly be water on the moon. Many felt there was a chance that the astronauts could bring back to earth some strange infection. These ideas are now known to be incorrect, and no doubt we are still wrong about many other things, also. Is the moon like the earth? 4. Yes and no. It is more like it than many scientists thought before Apollo. Like the earth, the moon is in layers, with a crust on the outside and a deep mantle below. It may also have a core, as the earth does. However, the crust is almost four times thicker than the earths crust. We do not know much yet about the moons mantle, that section of superheated rock which goes down hundreds of miles below the crust. We think-but we are not sure-that the moon has a center core which includes molten rock, as the earth does. 5. In other ways, of course, the moon is very different. There is no life, and there is no water. The makeup of its atmosphere is very different; the earth creatures cannot breathe in it. Of what is the moon made? 6. Definitely not green cheese. It has the same chemical elements as have the earth and the rest of the solar system but in very different amounts-more of some, less of others. Carbon, which is a very important part of living things on the earth, is rare on the moon. Is the moon hot or cold? 7. Most scientists agree that some of the moon was hot for at least a time. Rocks from the moon show that they were once melted. Right now there seems to be heat someplace inside the moon, possibly a great deal of it. On the surface, however, there is no sign of heat-no volcano, for example. The surface itself ranges from heat of 230℉ to cold of minus 290℉,depending upon where the sun is.
体坛英语资讯:Djokovic eases through, French Open champ Li exits at U.S. Open
体坛英语资讯:Turkeys Trabzonspor replaces Fenerbahce in Champions League draw
体坛英语资讯:Real crush Zaragoza 6-0 to open up La Liga
体坛英语资讯:Zico accepts offer to lead Iraqi national soccer team
体坛英语资讯:USA takes revenge on Brazil to retain World Grand Prix title
体坛英语资讯:Rodriguez takes stage and overall lead in Vuelta
体坛英语资讯:Adebayor moves to Spurs on loan
体坛英语资讯:Barcelona beat Porto to lift European Super Cup
体坛英语资讯:Cameroons soccer star Etoo to join Russian side Anzhi
体坛英语资讯:Jamaica looks to confront USA in womens 100m final
国际英语资讯:Abes shock resignation presents uncertainties for Japan
体坛英语资讯:Athletic in Europa League group stage without kicking a ball
体坛英语资讯:Will Chinas Zhang clear personal best again in mens high jump final in Daegu?
体坛英语资讯:Brazil, USA secure semifinal berths at FIVB WGP final round
体坛英语资讯:Italian soccer new season threatened by strike
体坛英语资讯:Kenyan womens medal sweep opens Daegu Worlds
国际英语资讯:Interview: Chinas clear future plans bring strong confidence to people at home, abroad --
体坛英语资讯:Santos defeats Fluminense 2-1
国际英语资讯:Peru extends emergency for 90 days amid COVID-19 resurgence
体坛英语资讯:Bayern wins, Cologne stuns Hamburg at German Bundesliga
国际英语资讯:UN-backed Libyan govt names new defense minister, chief of staff following protests
体坛英语资讯:Arsenal reaches agreement with Man City for Nasri move
国际英语资讯:ASEAN, China, Japan, S. Korea reaffirm commitment to actions against COVID-19 fallout
体坛英语资讯:Nadal, Murray, Del Potro reach U.S. Open third round
体坛英语资讯:Bolt steals limelight, Russian topples record
体坛英语资讯:Cameroonian football star EtoO joins Russian club
国际英语资讯:Top U.S. general says military wont play role in 2020 election
体坛英语资讯:Sao Paulo secures Henrique for five more seasons
体坛英语资讯:Worlds leading hurdlers safely advance in Daegu worlds
Water-splashing Festival 泼水节
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |