出版時(shí)間:2009-8 出版社:群言出版社 作者:哈爾,米爾奇,麥考馬克 頁數(shù):350 譯者:蔡青,劉洋
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內(nèi)容概要
《新托福考試專項(xiàng)進(jìn)階》系列叢書從托??荚囁疾榈穆牎⒄f、讀、寫四項(xiàng)技能人手,為考生提供了詳盡的考試指導(dǎo),并將各技能分為初、中、高三級(jí),逯過獨(dú)特的“進(jìn)階訓(xùn)練”方式,再輔以大量練習(xí),讓考生逐步掌握托福實(shí)考的技巧,同時(shí)切實(shí)提高英語實(shí)際運(yùn)用能力,從而在短期內(nèi)輕松取得托福高分。本叢書內(nèi)容編排由易到難,循序漸進(jìn),實(shí)戰(zhàn)性強(qiáng),是不可多得的托福備考資料。 本叢書引進(jìn)自韓國多樂園出版社。該社成立于1977年,在韓國英語教育出版領(lǐng)域始終處于領(lǐng)軍地位。本叢書被韓國眾多學(xué)校和培訓(xùn)機(jī)構(gòu)指定為課堂教材,在托福考生中享有較高聲譽(yù)。
書籍目錄
Contents PART 1 Basic Comprehension Unit 1 Vocabulary Biology/Sociology|Literature Unit 2 Reference Science|History|Economics Unit 3 FactuaIInformation Art/Geography|Politics Unit 4 Negative Factual Information Culture/Astronomy/Chemistry Unit 5 Sentence Simplification Ecology/Biology/Geology PART 2 Making Inferences Unit 6 RhetorlcaI Purpoae Zoology/Sociology/Literature|Language Unit 7 Inference Psychology/History/Geography Unit 8 lnsertText Art/Economics/Science PART 3 Reading to Learn Unit 9 Prose Summary Geology/Astronomy/Chemistry Unit l0 Fill in aTable Culture/Anthropology/Ecology|Biology Vocabulary Wrap-up ActuaITest 01 ActuaITest 02Contents(Answer Book) Unit 1 Vocabulary Unit 2 Reference Unit 3 Factual Information Unit 4 Negative Factual Information Unit 5 Sentence Simplification Unit 6 Rhetorical Purpose Unit 7 Inference Unit 8 InsertText Unit 9 Prose Summary Unit 10 Fill in a Table Actual Test 01 Actual Test 02
章節(jié)摘錄
The principles making radio possible were developed throughout the nineteenth century. The first breakthrough was by the British physicist Michael Faraday in 1831. He discovered that when an electric current passes through one wire, it produces a current in another wire even though the wires do not touch each other. In 1864, James Maxwell showed that this current——composed of electromagnetic waves——travels at the speed of light. Heinrich Hertz proved that the waves pass through solid objects. With these discoveries in place, the race was on to develop a system of wireless radio. Among the contenders was Reginald Fessenden, a Canadian inventor. Fessenden began experimenting with radio detectors in order to explore the possibility of voice transmission. In 1900, he was the first person to transmit his voice, but the sound was unrecognizable because the waves were not continuous. He invented a barreter detector, taking its name from the French word exchanger, to receive AM (amplitude modulated) signals, but it was not sensitive enough. One day in 1901, he accidentally left a filament of wire in acid for too long until only a tip of the wire was in contact with the acid. Fessenden noticed that, with the wire in the acid, the barreter was very sensitive to nearby continuous radio waves. Fessenden called his invention a liquid barreter, but it became known as an electrolytic detector. The detector consisted of several connected parts forming an electric circuit. A silver-coated platinum wire was dipped into a small platinum cup filled with nitric or sulfuric acid and connected to the ground. A battery was connected between the wire and the acid, prompting a current to flow in the detector. Someone wearing headphones that were hooked up to the detector could hear a hissing noise, which could be adjusted by turning a dial until the hissing noise stopped. At that point, the detector was highly sensitive to incoming radio waves.
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