清华大学2012年考博英语真题

　　医学博士英语统一考试之后，即将迎来各院校的考博英语初试，英语考试的备考，参考历年真题是一个很重要的备考过程，今天新东方在线小编给大家整理了清华大学2012年考博英语真题，帮助大家更好的备考，考博英语考试，一起来看看吧!

全国院校考博英语历年真题汇总

　　Scientists searching for precious metals have turned to the ocean floor, where natural chimneys are spewing out a metal-enriched black dust containing particles of gold, silver and zinc.

　　Scientists 31 these hot springs are recreating the process which, billions of years ago, created 32 metal deposits now found on land.

　　The discovery is giving geologists a 33 into the earth’s early history and fuelling some new theories on origin of life.

　　It also has huge implications for 34 companies.

　　Geologists are just beginning to understand how these chimneys, 35 clusters of sulphur and minerals, are formed, and what makes them spew out the mineralized dust.

　　At present it is not commercially 36 for mining companies to operate beneath the sea, although some scientists believe the “black smokers”, 37 known as active mineralizing systems, will be a major—and renewable—source of metals in the next decade.

　　38 the meantime, mining companies are using the ocean-floor research to locate similar deposits on land.

　　“The hottest thing in the mining research game right now is the 39 within the past few years of mineral deposits currently forming—in front of our eyes—on the ocean floor,” said Dr. Joseph Fox, a Montreal (加拿大蒙特利尔) geologist.

　　Canada has mined some of the richest copper, zinc and gold 40 in the world. In the past year, mining companies have used knowledge about where mineral formations 41 on the ocean floor to find the deposits on land.

　　Geologists are excited because, 42 metal deposits on land, which are two or three billion years old, the undersea deposits keep 43 themselves.

　　“It’s really incredible to think that we have a renewable metal resource 44 we’ve been taught to think of metal resources as non-renewable,” Fox said.

　　The 30-foot-high (10-metre) chimneys or vents, 45 in 1979, are found along fractures in the ocean’s crust.

　　Scientists believe the deposits form when cold sea-water seeps into the fractures, leaving metals 46 it is drawn down.

　　As the water travels in the direction of the earth’s core, it 47 up. Eventually, the hot water rises, carrying with it the hot metal sulphide 48 the ocean floor.

　　When the hot sulphide meets the cold sea water, a thick black smoke-like substance is formed, spewing out of vents in built-up deposits of 49 .

　　The particles in the smoke eventually 50 on the ocean floor, forming vast solid sheets of metal sulphide.

　　31. A. believe B. thought C. uncover D. found

　　32. A. smooth B. tiny C. vast D. rust

　　33. A. chance B. revision C. weapon D. glimpse

　　34. A. metal B. mining C. alloy D. global

　　35. A. made of B. consisting in C. resulted from D. dealing with

　　36. A. periodic B. reliable C. comparative D. feasible

　　37. A. formally B. chiefly C. economically D. occasionally

　　38. A. At B. On C. In D. For

　　39. A. invention B. discovery C. findings D. theory

　　40. A. samples B. deposits C. mines D. fractions

　　41. A. range B. suffer C. occur D. form

　　42. A. unlike B. like C. as D. except

　　43. A. to renew B. renewing C. having renewed D. to be renewed

　　44. A. before B. until C. because D. when

　　45. A. broken B. fixed C. discovered D. originated

　　46. A. since B. as C. for D. whereas

　　47. A. speeds B. goes C. gives D. heats

　　48. A. from B. on C. toward D. beyond

　　49. A. sulphide B. substance C. deposits D. element

　　50. A. rely B. move C. turn D. settle

2023考博精品好课，点击图片查看介绍！