Lesson 30 Exploring the sea-floor 海底勘探
First listen and then answer the following question. 聽錄音，然后回答以下問題。 How did people probably imagine the sea-floor before it was investigated? Our knowledge of the oceans a hundred 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 desposal of the royol sociaty for sevral cruises but the series of deep soundings was obtained in the Atlantic and the first samples were collected by dredging 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. 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-fatheom 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. 【參考譯文】 100年前，我們只知道海洋是二維平面形的，以及靠近陸地淺水區(qū)的深淺不一能給航行帶來危險(xiǎn)。無邊無際的海洋深邃而又神秘，凡是稍稍想過大海海底的人大概都會(huì)認(rèn)為海底是平坦的。1839年，詹姆斯.克拉克.羅斯爵士曾測得海水深度超過2，400英尋；但直到1869年，皇家學(xué)會(huì)用英國“豪豬”號(hào)艦艇進(jìn)行了幾次巡航后，才在大西洋測得一個(gè)海水深度，同時(shí)能過挖掘海底，取得了研究海底的首批樣品。此后不久，英國的“挑戰(zhàn)者”號(hào)艦艇對海底的那次考察，把對海床的研究確立為一個(gè)值得一流物理學(xué)家和地質(zhì)學(xué)家從事的研究課題，鋪設(shè)海底電纜的熱潮很快證實(shí)了“挑戰(zhàn)者”號(hào)的觀察結(jié)果：海洋中很多地方可深達(dá)兩三英里，水下特征差異極大。 現(xiàn)在已有足夠的水深測量數(shù)據(jù)來繪制一張大西洋洋底地形圖，而且我對海底地形的千變?nèi)f化也有了一定的了解。既然海洋覆蓋著地球的大部分表面，因此完全有理由把海床看作地殼的基本模殼，上面附加著大陸以及島嶼和海洋的其他形態(tài)。大陸是崎嶇不平的高地，高出遼闊的海洋海底近三英里。從海岸線向大海延伸幾英里到幾百英里的區(qū)域是大陸架慢坡，從地質(zhì)學(xué)上來說，它是大陸的一部分。大陸和海洋的真正分界線是在陡破腳下。 大陸架慢坡一般是從差不多100英尋水深的地方開始的，一直延伸到幾百英里遠(yuǎn)深達(dá)2，500至3，500的地方，那里才是真正的海底。坡度平均約為1/30，但其中包括陡峭的、乃至垂直的峭壁和沉積物覆蓋的緩和的階梯地帶，在這個(gè)地帶的低處是很長的一段尾沙地段，基本上可以斷定這個(gè)地段是大陸塊體上侵蝕下來的物質(zhì)被水沖到深水處形成的。1.navigation n.航海 例句：Navigation is difficult on this river because of hidden rocks. 由于多暗礁, 在這條河上航行很困難。
2.sounding n.水深度 例句：ocean remote sensing sounding 海洋遙感測深
3.fathom n.尋（1尋等于1.8米）
4.porcupine n.箭豬
例句：A porcupine is covered with prickles. 箭豬身上長滿了刺。 5.dredge v.挖掘 例句：They have to dredge the canal so that ships can use it. 他們須疏浚運(yùn)河河道輪船方可通航。
6.expedition n.遠(yuǎn)征 例句：The scientists will go on an expedition to the South Pole. 這些科學(xué)家們將要去南極考察。
7.physicist n.物理學(xué)家
8.magnitude n.很多 例句：The auditorium is a building of great magnitude. 這個(gè)大禮堂是一棟巨大的建筑物。
9.topography n.地形
10.crust n.地殼
11.rugged adj.崎嶇不平 例句：The Rocky Mountains have rugged mountains and roads. 落基山脈有崇山峻嶺和崎嶇不平的道路。
12.tableland n.高地
13.sediment n.沉淀物
14.terrace n.階地
15.erode v.侵蝕 例句：The coast is slowly eroding. 海岸正慢慢地被侵蝕。1.Our knowledge of the oceans a hundred 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. be confined to限于 例句：I shall hate to be confined in an office all day. 我討厭整天關(guān)在辦公室里。 The latter should be confined to the common struggle against the enemy. 后者應(yīng)約束于共同對敵的范圍之內(nèi)。 two-dimensional二維的，三維的用three-dimensional close to離…近 例句：His house is close to mine. 他的房子靠近我家。 It is close to fact. 這更接近于事實(shí)。 2.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. anyone who，任何一個(gè)人。也可以用whoever來代替。這里要注意的是，anyone,some,nothing等后面跟定語從句時(shí)只能用that引導(dǎo)，而不能用which。 3.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. Shortly after之后不久。 引申：long before before long before long =soon，a little later不久以后 作時(shí)間狀語，可用于將來時(shí)或過去時(shí)。 例：I hope to see you before long. 我希望不久能見到你。 Before long they had got everything ready. 不久他們就做好了一切準(zhǔn)備。 long before=long long ago很久以前 表示過去，可單獨(dú)作狀語，其后還可接從句或名詞。 例：We heard of it long before. 我們很久以前就聽說過這件事。 It will be long before he arrives. 還要很久他才到達(dá)。 4.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. a burst of表示突發(fā)；猝發(fā)；迸發(fā)；爆破 burst還有動(dòng)詞的意思： 爆炸, 爆裂，脹開 例句：The dam burst under the weight of water. 那水壩在水的壓力下決口了。 If you get much fatter you'll burst your clothes. 你要是再長胖就要把衣服撐破了。 considerable a.相當(dāng)?shù)?可觀的,重要的;相當(dāng)大的;相當(dāng)多的 例句：He still suffers considerable discomfort from his injury. 他因那次受傷至今仍頗感不適。 注意不要和一個(gè)形近詞混淆： considerate a.考慮周到的;體諒的,替…著想的 例句：He is considerate of others. 他很體諒別人。 5.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. it形式主語，真正的主語是后面的不定式。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. average用法 a. 用作名詞，注意以下用法： (1) 表示“平均”、“平均數(shù)”，是可數(shù)名詞。如： The average of 6，8 and 10 is 8. 6，8，10的平均數(shù)是8。 An average of 10 students are absent each day. 平均每天有10個(gè)學(xué)生缺席。 It’s said thatthe paper receive an average of nearly 100 articles a day. 據(jù)說這個(gè)報(bào)社平均每天要收到百來篇來稿。 (2) 表示“普通”、“標(biāo)準(zhǔn)”、“平?！钡龋ù笾孪喈?dāng)于“一般水平”的意思)，根據(jù)情況可用作可數(shù)或不可數(shù)名詞。如： Tom’s work atschool is above (the) average, Jim’s is below (the) averageand Jack’s is up to (the) average. 湯姆的學(xué)習(xí)成績屬于中上水平，吉姆的學(xué)習(xí)成績屬中下水平，杰克的學(xué)習(xí)成績屬中等水平。 (3) 表示“平均起來”、“在一般情況下”，可用 on average, onan (the) average。如： On (the) average we receive ten letters eachday. 我們平均每天收到10封信。 He smokes 20 cigarettes a dayon an average. 他平均每天要抽20支煙。 b.用作形容詞，注意以下用法： (1) 表示“平均的”，通常只能放在名詞前作定語，不用作表語，且沒有比較等級。如： What was the average temperature yesterday? 昨天的平均氣溫是多少? The average age of the boys in thisclass is fifteen. 這個(gè)班男生的平均年齡為15歲。 (2) 表示“一般的”、“普通的”，可用作定語也可用作表語。如： Heis just an average student. 他只是個(gè)普通的學(xué)生。 There wasnothing special about the film---it was only average. 這部電影沒什么特別的---只是部普通的電影。 c.用作動(dòng)詞，通常為及物動(dòng)詞： He averages two trips a year. 他平均每年旅游兩次。 The hotel averages 50 to 100 foreignguests daily. 這家旅館平均每天接待50 至100 名外國客人。 Thechildren average 10 years of age. 這些小孩平均年齡為10歲。 在現(xiàn)代英語中，類似以下用法的 average 被看作是連系動(dòng)詞 (或不及物動(dòng)詞)。如： Our mail averages 20 letters a day. 我們平均每天收到10封信。1.Our knowledge of the oceans a hundred 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. 100年前，我們只知道海洋是二維平面形的，以及靠近陸地淺水區(qū)的深淺不一能給航行帶來危險(xiǎn)。 2.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 bad was flat. 無邊無際的海洋深邃而又神秘，凡是稍稍想過大海海底的人大概都會(huì)認(rèn)為海底是平坦的。 3.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. 現(xiàn)在已有足夠的水深測量數(shù)據(jù)來繪制一張大西洋洋底地形圖，而且我對海底地形的千變?nèi)f化也有了一定的了解。 4.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. 從海岸線向大海延伸幾英里到幾百英里的區(qū)域是大陸架慢坡，從地質(zhì)學(xué)上來說，它是大陸的一部分。
First listen and then answer the following question. 聽錄音，然后回答以下問題。 How did people probably imagine the sea-floor before it was investigated? Our knowledge of the oceans a hundred 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 desposal of the royol sociaty for sevral cruises but the series of deep soundings was obtained in the Atlantic and the first samples were collected by dredging 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. 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-fatheom 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. 【參考譯文】 100年前，我們只知道海洋是二維平面形的，以及靠近陸地淺水區(qū)的深淺不一能給航行帶來危險(xiǎn)。無邊無際的海洋深邃而又神秘，凡是稍稍想過大海海底的人大概都會(huì)認(rèn)為海底是平坦的。1839年，詹姆斯.克拉克.羅斯爵士曾測得海水深度超過2，400英尋；但直到1869年，皇家學(xué)會(huì)用英國“豪豬”號(hào)艦艇進(jìn)行了幾次巡航后，才在大西洋測得一個(gè)海水深度，同時(shí)能過挖掘海底，取得了研究海底的首批樣品。此后不久，英國的“挑戰(zhàn)者”號(hào)艦艇對海底的那次考察，把對海床的研究確立為一個(gè)值得一流物理學(xué)家和地質(zhì)學(xué)家從事的研究課題，鋪設(shè)海底電纜的熱潮很快證實(shí)了“挑戰(zhàn)者”號(hào)的觀察結(jié)果：海洋中很多地方可深達(dá)兩三英里，水下特征差異極大。 現(xiàn)在已有足夠的水深測量數(shù)據(jù)來繪制一張大西洋洋底地形圖，而且我對海底地形的千變?nèi)f化也有了一定的了解。既然海洋覆蓋著地球的大部分表面，因此完全有理由把海床看作地殼的基本模殼，上面附加著大陸以及島嶼和海洋的其他形態(tài)。大陸是崎嶇不平的高地，高出遼闊的海洋海底近三英里。從海岸線向大海延伸幾英里到幾百英里的區(qū)域是大陸架慢坡，從地質(zhì)學(xué)上來說，它是大陸的一部分。大陸和海洋的真正分界線是在陡破腳下。 大陸架慢坡一般是從差不多100英尋水深的地方開始的，一直延伸到幾百英里遠(yuǎn)深達(dá)2，500至3，500的地方，那里才是真正的海底。坡度平均約為1/30，但其中包括陡峭的、乃至垂直的峭壁和沉積物覆蓋的緩和的階梯地帶，在這個(gè)地帶的低處是很長的一段尾沙地段，基本上可以斷定這個(gè)地段是大陸塊體上侵蝕下來的物質(zhì)被水沖到深水處形成的。1.navigation n.航海 例句：Navigation is difficult on this river because of hidden rocks. 由于多暗礁, 在這條河上航行很困難。
2.sounding n.水深度 例句：ocean remote sensing sounding 海洋遙感測深
3.fathom n.尋（1尋等于1.8米）
4.porcupine n.箭豬
例句：A porcupine is covered with prickles. 箭豬身上長滿了刺。 5.dredge v.挖掘 例句：They have to dredge the canal so that ships can use it. 他們須疏浚運(yùn)河河道輪船方可通航。
6.expedition n.遠(yuǎn)征 例句：The scientists will go on an expedition to the South Pole. 這些科學(xué)家們將要去南極考察。
7.physicist n.物理學(xué)家
8.magnitude n.很多 例句：The auditorium is a building of great magnitude. 這個(gè)大禮堂是一棟巨大的建筑物。
9.topography n.地形
10.crust n.地殼
11.rugged adj.崎嶇不平 例句：The Rocky Mountains have rugged mountains and roads. 落基山脈有崇山峻嶺和崎嶇不平的道路。
12.tableland n.高地
13.sediment n.沉淀物
14.terrace n.階地
15.erode v.侵蝕 例句：The coast is slowly eroding. 海岸正慢慢地被侵蝕。1.Our knowledge of the oceans a hundred 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. be confined to限于 例句：I shall hate to be confined in an office all day. 我討厭整天關(guān)在辦公室里。 The latter should be confined to the common struggle against the enemy. 后者應(yīng)約束于共同對敵的范圍之內(nèi)。 two-dimensional二維的，三維的用three-dimensional close to離…近 例句：His house is close to mine. 他的房子靠近我家。 It is close to fact. 這更接近于事實(shí)。 2.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. anyone who，任何一個(gè)人。也可以用whoever來代替。這里要注意的是，anyone,some,nothing等后面跟定語從句時(shí)只能用that引導(dǎo)，而不能用which。 3.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. Shortly after之后不久。 引申：long before before long before long =soon，a little later不久以后 作時(shí)間狀語，可用于將來時(shí)或過去時(shí)。 例：I hope to see you before long. 我希望不久能見到你。 Before long they had got everything ready. 不久他們就做好了一切準(zhǔn)備。 long before=long long ago很久以前 表示過去，可單獨(dú)作狀語，其后還可接從句或名詞。 例：We heard of it long before. 我們很久以前就聽說過這件事。 It will be long before he arrives. 還要很久他才到達(dá)。 4.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. a burst of表示突發(fā)；猝發(fā)；迸發(fā)；爆破 burst還有動(dòng)詞的意思： 爆炸, 爆裂，脹開 例句：The dam burst under the weight of water. 那水壩在水的壓力下決口了。 If you get much fatter you'll burst your clothes. 你要是再長胖就要把衣服撐破了。 considerable a.相當(dāng)?shù)?可觀的,重要的;相當(dāng)大的;相當(dāng)多的 例句：He still suffers considerable discomfort from his injury. 他因那次受傷至今仍頗感不適。 注意不要和一個(gè)形近詞混淆： considerate a.考慮周到的;體諒的,替…著想的 例句：He is considerate of others. 他很體諒別人。 5.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. it形式主語，真正的主語是后面的不定式。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. average用法 a. 用作名詞，注意以下用法： (1) 表示“平均”、“平均數(shù)”，是可數(shù)名詞。如： The average of 6，8 and 10 is 8. 6，8，10的平均數(shù)是8。 An average of 10 students are absent each day. 平均每天有10個(gè)學(xué)生缺席。 It’s said thatthe paper receive an average of nearly 100 articles a day. 據(jù)說這個(gè)報(bào)社平均每天要收到百來篇來稿。 (2) 表示“普通”、“標(biāo)準(zhǔn)”、“平?！钡龋ù笾孪喈?dāng)于“一般水平”的意思)，根據(jù)情況可用作可數(shù)或不可數(shù)名詞。如： Tom’s work atschool is above (the) average, Jim’s is below (the) averageand Jack’s is up to (the) average. 湯姆的學(xué)習(xí)成績屬于中上水平，吉姆的學(xué)習(xí)成績屬中下水平，杰克的學(xué)習(xí)成績屬中等水平。 (3) 表示“平均起來”、“在一般情況下”，可用 on average, onan (the) average。如： On (the) average we receive ten letters eachday. 我們平均每天收到10封信。 He smokes 20 cigarettes a dayon an average. 他平均每天要抽20支煙。 b.用作形容詞，注意以下用法： (1) 表示“平均的”，通常只能放在名詞前作定語，不用作表語，且沒有比較等級。如： What was the average temperature yesterday? 昨天的平均氣溫是多少? The average age of the boys in thisclass is fifteen. 這個(gè)班男生的平均年齡為15歲。 (2) 表示“一般的”、“普通的”，可用作定語也可用作表語。如： Heis just an average student. 他只是個(gè)普通的學(xué)生。 There wasnothing special about the film---it was only average. 這部電影沒什么特別的---只是部普通的電影。 c.用作動(dòng)詞，通常為及物動(dòng)詞： He averages two trips a year. 他平均每年旅游兩次。 The hotel averages 50 to 100 foreignguests daily. 這家旅館平均每天接待50 至100 名外國客人。 Thechildren average 10 years of age. 這些小孩平均年齡為10歲。 在現(xiàn)代英語中，類似以下用法的 average 被看作是連系動(dòng)詞 (或不及物動(dòng)詞)。如： Our mail averages 20 letters a day. 我們平均每天收到10封信。1.Our knowledge of the oceans a hundred 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. 100年前，我們只知道海洋是二維平面形的，以及靠近陸地淺水區(qū)的深淺不一能給航行帶來危險(xiǎn)。 2.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 bad was flat. 無邊無際的海洋深邃而又神秘，凡是稍稍想過大海海底的人大概都會(huì)認(rèn)為海底是平坦的。 3.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. 現(xiàn)在已有足夠的水深測量數(shù)據(jù)來繪制一張大西洋洋底地形圖，而且我對海底地形的千變?nèi)f化也有了一定的了解。 4.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. 從海岸線向大海延伸幾英里到幾百英里的區(qū)域是大陸架慢坡，從地質(zhì)學(xué)上來說，它是大陸的一部分。