【正文】 南下的奧德修斯一行人漂到了風神所在的島。大家拼命劃槳才脫離了險境，隨后來到太陽神赫利俄斯居住的特里那基耶島。但是，在 1870 年以前，歷史學家根據當時掌握的史料，只能將希臘的歷史追溯到公元前 78 世 紀。汞在大氣中呈蒸汽態(tài)，因而雨水中也有汞，平均濃度為 。在人體其他組織中的金屬汞，可能氧化成離子狀態(tài)，并轉移到腎中蓄積起來。貓因為吃魚多，所以先中毒。 等恒星的半徑小到一特定值（天文學上叫“史瓦西半徑”）時，就連垂直表面發(fā)射的光都被捕獲了。那幺，黑洞是怎幺把自己隱藏起來的呢？答案就是 —— 彎曲的空間。 較大的氣態(tài)行星：木星，土星，天王星和海王星： 氣態(tài)行星主要由氫和氦構成，密度低，自轉速度快， 大氣層厚，有光環(huán)和很多衛(wèi)星。 離太陽與地球較遠。體微小，構造簡單，單或多細胞，也有無細胞的。此外還分：靠化學反應合成有機物的化能合成細菌和靠光合作用生產有機物的光合自養(yǎng)菌，如藍藻菌；以它們合成的有機物為營養(yǎng)來源的異養(yǎng)細菌。很多真菌還可以做成美味佳肴 ...但也有一些種類危害人類健康或給人類帶來各種經濟損失。 病毒的繁殖：病毒是專性活細胞內寄生物。60s, and late 39。 the introduction of contour plowing, terracing, and strip planting。并且，一種病毒只擁有一種類型的核酸，要么是 DNA，要么是 RNA。 真菌適應性很強 ,幾乎到處都有分布 .在自然界里 ,能分解各種有機物 ,如纖維素 ,木質素等 ,在增加土壤肥力以及自然界的物質循環(huán)上起著重要的作用 ,它們與人類的關系非常密切 ,不少種類的真菌如青霉菌為人類制造重要的抗生素 。但青霉素可以阻止它的合成，從而殺死細菌。s normal velocity. 托福聽力背景知識 (八 ) 微生物背景材料 微生物 微生物是生物中的一大類，與植物和動物共同組成生物界。 地球。有興趣的朋友可以去參考專門的論著。 與別的天體相比，黑洞是顯得太特殊了。當恒星的體積很大時，它的引力場對時空幾乎沒什幺影響，從恒星表面上某一點發(fā)的光可以朝任何方向沿直線射出。為什么貓會先得病呢？這是因為貓去吃水俁灣里的魚，而水俁灣的水受到污染汞含量超標。試驗表明，成年人每天攝人 毫克的甲基汞，由于人體排泄能力使之不會在身體內累積，若攝入量超過人體的排泄能力，會在體內累積。汞的本底對判斷環(huán)境中的汞污染程度很有意義。因為希臘人開啟了西方哲學、科學、藝術、文學和歷史。在同伴的一致要求下，奧德修斯告別塞西繼續(xù)航行，在經過海妖塞壬的島時，奧德修斯用塞西教的方法用蠟將同伴們的耳朵都封起來，再把自己綁在船桅上，這樣他們才沒被塞壬的甜蜜歌聲引誘而斷送性命。獨眼巨人波呂斐摩斯（海神波塞冬的兒子）非常殘忍，把奧德修斯和他帶上岸的 12 名屬下關進巖洞里，每天吃掉 2 個人。帕里斯知道了阿基里斯的這個弱點，從遠處用暗箭射中他的腳跟，殺死了英雄阿基里斯。戰(zhàn)爭進行了 10 年之久，希臘世界的英雄們紛紛登場出戰(zhàn)。厄里斯便挑起是非，偷偷把一個寫著“送給最美麗的女神”的金蘋果放在了婚禮宴席上。當 3 位女神見到帕里斯后，都爭著向他許愿：赫拉愿給他權力和財寶；雅典娜愿給他勝利和智慧；阿芙羅狄蒂愿讓他挑選世界上最美麗的女子為妻。這個時候，戰(zhàn)爭已僵持不下，而希臘聯軍內部也發(fā)生了矛盾。 最后，足智多謀的奧德修斯獻出了“木馬計”，米阿加米農所采納。風神送給他們一只風袋，西風送他們一行往東平安地通過西西里島和意大利半島之間的墨西拿海峽駛入愛奧尼亞海。由于糧食耗盡，幾個同伴趁奧德修斯睡著之際偷殺了太陽神養(yǎng)的神牛。盡管家喻戶曉的“荷馬史詩”描述了希臘史前的故事，但學者們認為，盲詩人荷馬的史詩，最初是許多民間行吟歌手的集體口頭創(chuàng)作，因而不能當作歷史，只能視為神話傳說。水中汞的本底濃度，內陸地下水為，海水為 一 2ppb，泉水可達 80ppb 以上，湖水、河水一般不超過 。人體受汞慢性中毒的臨床表現，主要是神經性癥狀，有頭痛、頭暈、肢體麻木和疼痛、肌肉震顫、運動失調等。貓得了舞蹈病，也就是水俁病，這時人還可以進行及時的救治。到這時，恒星就變成了黑洞。我們都知道，光是沿直線傳播 的。 冥王星。 地外行星看起來通常是完整的，或近乎完整的。分布廣泛，繁殖快且類型多樣。還有厭氧細菌；好氧細菌和兼性細菌。但總的來說 ,真菌對 人類還是大有益處的。它不能單獨進行繁殖，必須在活細胞內才能繁殖。70s were responsible for recurrences of dust storms in the region. 補充：由于 dust bowl 導致的洛杉磯地區(qū)的移民增加 In the 1930s and 1940s, the region also received two waves of major migrations: that of farm families from the southern Great Plains migrating west to escape the Dust Bowl, and that of African Americans moving out of the American South. During World War II (19391945) the need for labor, especially in ship and aircraft production, boosted the population even more. The population of Los Angeles County jumped from 3 million to million between 1940 and 1950. 托福聽力背景知識 (十 ) 天上掉鉆石 Is It Raining Diamonds On Uranus？ Berkeley October 1, 1999 If experiments at the University of California, Berkeley, are any indication, future explorers of our solar system may well find diamonds hailing down through the atmospheres of Neptune and Uranus. These plas contain a high proportion of methane, which UC Berkeley researchers have now shown can turn into diamond at the high temperatures and pressures found inside these plas. Once these diamonds form, they fall like raindrops or hailstones toward the center of the pla, said Laura Robin Benedetti, a graduate student in physics at UC Berkeley. The team, led by Benedetti and Raymond Jeanloz, professor of geology and geophysics, produced these conditions inside a diamond anvil cell, squeezing liquid methane to several hundred thousand times atmospheric pressure. When they focused a laser beam on the pressurized liquid, heating it to some 5,000 degrees Fahrenheit, diamond dust appeared. They report their experimental findings in a paper in the Oct. 1 issue of Science. The demonstration that methane can convert to diamond as well as other plex hydrocarbons in the interiors of giant plas like Neptune hint at a plex chemistry inside gaseous plas and even brown dwarf stars. Brown dwarfs are small, dim stars barely larger than the largest gas giant plas. This is opening the door to study of the interesting types of chemical reactions taking place inside plas and brown dwarfs, Jeanloz said. Now that technology is able to reproduce the high pressures and temperatures found there, we are getting much better quality information on the chemical reactions taking place under these conditions. It is not amazing that chemistry like this happens inside plas, it39。 3year rotation of wheat and shum and of lying fallow。大多數病毒是由核酸和蛋白質組成的。真菌與植物的主要區(qū)別在 于 :真菌貯藏的養(yǎng)料是肝糖 ,而綠色植物主要是淀粉。細菌的細胞壁由肽聚糖組成，十分堅固。s mass balance. To find mass balance, scientists measure the area of each region and observe amounts of accumulation and ablation relative to preset stakes. After density measurements are made they may calculate how much water has been added or lost to the glacier. After a series of positive mass balance years, the glacier may respond to the increased thickness by making a glacial advance downvalley. A series of negative years may cause a glacial retreat, meaning that the terminus is melting faster than the ice is moving downvalley. Glaciers have been likened to mighty rivers of ice. Although they move many times more slowly, glaciers have equivalent changes in flow rate and often form falls of fastmoving ice above slowmoving ice pools. Glaciers flow faster down their centers than at ice margins, and more quickly at the surface than at the bed. ... How fast a glacier moves is mostly dependent on the thickness of the ice, and on the angle of its surface slope. Glacier speeds vary when changes are made in this geometry. They respond to excessively high seasonal snow accumulations by generating bulges of thicker ice that may move downvalley many times faster than the glacier39。 地內行 星看起來的如同地球上看有時不完整的月亮。不過，這些當代天體物理學的最新成果不是在這里三言兩語能說清楚的。而當它的半徑一旦收縮到一定程度 (史瓦西半徑 )，正象我們上面介紹的那樣，巨大的引力就使得即使光也無法向外射出，從而切斷了恒星與外