一轮复习必修三第四单元 Astronomy.pptx

Astronomy: the science of the stars;Unit 4　Astronomy: the science of the stars revision;Unit 4　Astronomy: the science of the stars;—— 精 彩 美 文 —— UFO, which is short for Unidentified Flying Object, has long been regarded as one of the top 10 unsolved mysteries in the world. The first UFO sighting was reported to have happened in America in 1878. Since then, numerous sightings have been reported all over the world, many of which turned out to be false.;Some people think UFOs are spaceships from other planets, others believe that theyre just a kind of natural phenomenon and still others guess theyre aliens. Now about one third of the countries in the world are doing research on UFOs, about which many books and journals have been published, and in some universities courses are even set up to study UFOs.;—— 名 师 点 睛 —— 1．文章体裁：说明文。 2．行文逻辑：介绍UFO→人们的看法→研究状况。 3．词汇短语：运用了较高级的词汇和短语。如：be short for(是……的简称)，be regarded as(被认为是……)，turn out(结果……)，set up(建立，成立)等。 4．句式句法：运用了多样化的句式结构。如：①定语从句：which is short for Unidentified Flying Object, many of which turned out to be false, about which many books and journals have been published；②宾语从句：that theyre just a kind of natural phenomenon and still others guess theyre aliens等。;Secton II --Vocabulary Usage 1．Not long ago a v________ earthquake occurred off the coast of Indonesia. 2．Computer hackers have broken down security s________，raising questions about the safety of information. 3．Salt d________ in water and becomes part of it. 4．He spent the whole afternoon p________ weeds in the garden. 5．Whenever recession(衰退) strikes, it sets off a chain r________in the international money markets.;6．There is a friendly ________ (气氛) of helping each other with difficulties in study in our class. 7．There are many ________(理论) about the origin of life. 8．Her school report shows that she is weak in maths and ________(生物学)． 9．He was interested in ________(天文学) and always stayed up at night to watch the stars. 10．6 ________(乘) by 5 is 30.;Ⅱ.短语检测