首页
登录
职称英语
Our knowledge of the oceans hundreds of years ago was confined to the two-di
Our knowledge of the oceans hundreds of years ago was confined to the two-di
游客
2024-09-16
19
管理
问题
Our knowledge of the oceans hundreds of years ago was confined to the two-dimensional shape of the sea surface and the hazards of navigation presented by the irregularities in depth of the shallow water close to the land. The open sea was deep and mysterious, and anyone who gave more than a passing thought to the bottom confines of the oceans probably assumed that the sea bed was flat. Sir James Clark Ross had obtained a sounding of over 2,400 fathoms in 1839, but it was not until 1869, when H.M.S. Porcupine was put at the disposal of the Royal Society for several cruises, that a series of deep soundings was obtained in the Atlantic and the first samples were collected by dredging (挖掘) the bottom. Shortly after this the famous H.M.S. Challenger expedition established the study of the sea-floor as a subject worthy of the most qualified physicists and geologists. A burst of activity associated with the laying of submarine cables soon confirmed the Challenger’s observation that many parts, of the ocean were two to three miles deep, and the existence of underwater features of considerable magnitude.
Today, enough soundings are available to enable a relief map of the Atlantic to be drawn and we know something of the great variety of the sea bed’s topography (地形). Since the sea covers the greater part of the earth’s surface, it is quite reasonable to regard the sea floor as the basic form of the crust of the earth, with, superimposed upon, it the continents, together with the islands and other features of the oceans. The continents form rugged tablelands which stand nearly three miles above the floor of the open ocean. From the shore line, out a distance which may be anywhere from a few miles to a few hundred miles, runs the gentle slope of the continental shelf, geologically part of the continents. The real dividing line between continents and oceans occurs at the foot of a steeper slope.
This continental slope usually starts at a place somewhere near the 100-fathom mark and in the course of a few hundred miles reaches the true ocean floor at 2,500-3,500 fathoms. The slope averages about 1 in 30, but contains steep, probably vertical, cliffs, and gentle sediment-covered terraces, and near its lower reaches there is a long tailing-off which is almost certainly the result of material transported out to deep water after being eroded from the continental masses. [br] The H.M.S. Challenger expedition
选项
A、was devoted to dredging the ocean.
B、was dedicated to laying submarine cables.
C、gave the sea-floor study disciplinary independence.
D、obtained a series of deep soundings in the Atlantic.
答案
C
解析
根据题干的H.M.S.Challenger expedition定位到第1段倒数第2句。该句指出:“‘挑战者’号舰船对海底进行了考察,把对海床的研究确立为一个值得一流物理学家和地质学家从事的研究课题。”由此可见,正是这次考察使得海床研究成为了独立的学科。故C为本题答案。A显然张冠李戴,文中明确指出,英国“豪猪”号舰船通过挖掘获得了首批海底样品,排除A;铺设海底电缆的热潮发生在“挑战者”号舰船考察之后,并证明了“挑战者”号考察的结果,故B也排除;测得大西洋水深的是“豪猪”号舰船,不是“挑战者”号,故D也排除。
转载请注明原文地址:https://tihaiku.com/zcyy/3760873.html
相关试题推荐
Aftergoingoversomebasicknowledgeabouthearing,theteacherwillleadthes
Aftergoingoversomebasicknowledgeabouthearing,theteacherwillleadthes
Aftergoingoversomebasicknowledgeabouthearing,theteacherwillleadthes
[A]acknowledged[B]conducted[C]consideration[D]convert[E]establishment[F]involve
[A]acknowledged[B]conducted[C]consideration[D]convert[E]establishment[F]involve
[A]acknowledged[B]conducted[C]consideration[D]convert[E]establishment[F]involve
[A]acknowledged[B]conducted[C]consideration[D]convert[E]establishment[F]involve
[A]acknowledged[B]conducted[C]consideration[D]convert[E]establishment[F]involve
[audioFiles]2016m8x/audio_ezfj_ezflisteningd_201607_183[/audioFiles]Oceans
Ourknowledgeoftheoceanshundredsofyearsagowasconfinedtothetwo-di
随机试题
了解求助者的既往史时,应该包括的内容是()A.评论以往心理咨询过程中出现的失误
王大娘,71岁,早晨上台阶时,摔倒在地(臀部着地),不能站立和行走,自感局部剧痛
关于耳的叙述正确的是()。A.鼓膜中央向内凹陷,称为鼓膜脐 B.耳郭下方1/
除交易所交易的标准化期权、权证之外,还存在大量场外交易的期权,这些新型期权通常被
共用题干 Animal's"SixthSense"Atsunamiwas
某医院药库工作人员正在验收麻精类药品入库保存,应当遵循的原则是A.货到即检、单人
患者女性,46岁。3年前因手术输血感染艾滋病,现服用AZT治疗。为检测该药物副作
获取与选择供应商报价最正规的方法是()。 A.正式招标法 B.询价—报
下列哪项不属于镇痛药的使用原则A.口服给药,尤其是强阿片类 B.按时给药 C
某食品公司2020年2月与其他企业订立专有技术使用权转移书据一份,所载金额60万
最新回复
(
0
)