| 71. | It 'flies', therefore, but it cannot fly higher -- its action depends on the surface , water or ground, over which it rides. |
| 这样，船就能飞了，但飞不高。它的飞行限决于它所悬浮的水面或地面。
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| 72. | 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，我们只知道海洋是二维平面形的，以及靠近陆地浅水区的深浅不一能给航行带来危险。
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| 73. | Because the Moon has only an eightieth of the Earth's mass, it requires 97 per cent less energy to travel the quarter of a million miles from the Moon to Earth-orbit than the 200 mile-journey from Earth's surface into orbit! |
| 因为月球的重只有地球的1/8，因此，从月球到地球的25万英里所消耗的能量要比从地球表面进入地球轨道的200英里所耗能量少97%。
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| 74. | Because the gravity on the Moon's surface is only a sixth of Earth's ( remember how easily the Apollo astronauts bounded along), it takes much less energy to accelerate to that 1.5 miles per second than it does on Earth. |
| 由于月球表面的重力仅是地球表面的1/6 -- 还记得阿波罗飞船中的宇航员累松地跳跃 -- 在月球上加速到每秒1.5英里比在地球上所用能源要少得多。
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| 75. | Once waves have been generated, gravity is the force that drives them in a continual attempt to restore the ocean surface to a flat plain. |
| 一旦波浪形成，地球引力是持续不断企图使海面复原为平面的力量。
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| 76. | The third, or main wave, is the slowest and has travelled round the earth through the surface rocks. |
| 第三种波，即主波，是最慢的，是围绕地球通过表面岩石传来的。
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| 77. | The contribution of the guide surface roughness overshadows that of the fiber surface roughness. |
| 导纱杆表面粗糙度的作用超过纤维表面的粗糙度。
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| 78. | The surface lipids undergo oxidation generating many compounds containing hydroxyl and carbonyl groups. |
| 表面的类脂物氧化后，产生许多化合物，包括羟基和羰基化合物。
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| 79. | American spacecrafts have passed close to Venus and Russian ones have parachuted instruments to its surface . |
| 美国的宇宙飞船曾经很近地经过金星，苏联的宇宙飞船已把仪器降落到它的表面上。
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| 80. | The water rat, paralysed and string, saw at last a distant speck on the white surface of the road. |
| 水老鼠神思恍惚，木然远望，终于看见一个小斑点出现在远方洁白的路面上。
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