Passage 1
1. Most of the world’s potable water----freshwater suitable for drinking----is accounted for by groundwater， which is stored in the pores and fractures in rocks.
分析：which引导的非限制性定语从句，修饰groundwater，account for是固定的短语，意为“对…做出解释；说明……的原因；导致；(比例)占”，这里解释为“(比例)占”。
喷淋泵 译文：世界上绝大部分的饮用水——比如可以饮用的淡水——都是地下水，它们储藏在岩石孔隙和裂缝中。
2. There is more than 50 times as much freshwater stored underground than in all the freshwater rivers and lakes at the surface.
分析：这句话的结构是“A is倍数+比较级+than B”，意为“A比B多几倍”。
译文：储藏于地下的淡水比地表中的淡水河流和湖泊的总水量还多50倍。
3. At greater depths within Earth， the pressure of the overlying rock caus pores 春节日记
and cracks to clo， reducing the space that pore water can occupy， and almost complete closure occurs at a depth of about 10 kilometers.
分析：reducing the space现在分词作状语，表结果；that引导的是定语从句，修饰the space；and引导的是两个并列句。
译文：随着深度的增加，上覆岩层的压力使岩石孔隙和裂缝闭合了，减少了孔隙水的储存空间；另外， 10公里深的地下孔隙也几乎完全闭合了。
4. A groundwater rervoir from which water can be extracted is called an aquifer.
分析：which引导的是定语从句，修饰rervoir，rervoir在从句中充当宾语；extract from是固定的短语，意为“从......抽取”。
译文：可以抽取出地下水的地下水库叫做蓄水层。
5. The more poorly sorted or the more tightly compacted diment is， the lower its porosity and permeability.
分析：这句话的结构是“the+比较级+陈述句，the+比较级+陈述句”，意为“越...越...”
译文：沉积物分选得越差或压实得越紧，则其孔隙度和渗透率就越低。
真想跟你做到死 6. Sedimentary rocks----the most common rock type near the surface----are also the most common rervoirs for water becau they contain the most space that can be filled with water.
分析：这句话是由becau引导的原因状语从句，主句是Sedimentary rocks----the 其中，第一个破折号的内容是对dimentary rocks的解释说明，第二个破折号的内容才是这句话的主干信息；becau从句中that引导的是定语从句，修饰space，space在定语从句中充当主语。
译文：沉积岩——地表最常见的岩石——也是最常见的水储集层，因为它们拥有最多的可储水的孔隙空间。
7. In some cas， the water table reaches Earth’s surface， where it is expresd as rivers， lakes and marshes.国二考试时间
分析：句中的where引导的是状语从句，修饰Earth’s surface，it指代the water table。
米黄是什么颜色 译文：某些情况下，地下水位将到达地表，在那里它以河流、湖泊或沼泽地的形式存在。
8. Water in the vado zone drains down to the water table， leaving behind a thin coating of water on mineral grains.
分析：leaving behind a thin coating of water on mineral grains现在分词作状语，表结果。
译文：包气带中的水沉降到地下水位，只有在矿物颗粒表面留下了一层水膜。
9. Becau the surface of the water table is not flat but instead ris and falls with topography， groundwater is affected by gravity in the same fashion as surface water.
秋分谚语 分析：这句话是由becau引导的原因状语从句，主句是groundwater is affected by gravity in the same fashion as surface water，被动语态。
译文：因为地下水位表面并非水平，而是沿着地势起伏，所以地下水和地表水受到重力影响的模式是相同的。
10. If the water table intercts the land surface， groundwater will flow out onto the surface at springs， whether to be collected there or to subquently flow farther along a drainage.
分析：这句话是由if引导的条件状语从句，主句是groundwater will flow out onto the surface ；whether to be 是对groundwater的解释说明。
译文：如果地下水位与地表相交，地下水将以喷泉的形式流出地面，流出地面的地下水或就地聚集、或沿排水通道流向更远的地方。
Passage 2
1. As recently as 6,000 B.C. the southern frontier of the dert was far to the north of where it is now, while miarid grassland and shallow freshwater lakes covered much of what are now arid plains.
分析：这句话是由while引导的时间状语从句，主句是the southern frontier of the ;其中of where it is now，where it is now是of的宾语，of后面的宾语本来是it is now，但是这样的话句子中就多了一个动词，英语中一个句子不能有多个动词，所以it is now用where引导，变成宾语从句，it指代前面的the southern frontier;同样地，of what are now arid plains中的what are now arid plains也是of的宾语
译文：在公元前6000年前，沙漠的南部边界在现在的南边以北很多的地方，那时半干旱的草原和浅淡水湖泊覆盖了现在是干旱平原的地方。
2. The areas that are now dert were, like all arid regions, very susceptible to cycles of higher and lower levels of rainfall, resulting in major, sudden changes in distributions of plants and animals.
分析：这句话的主干是the areas were susceptible to cycles of higher and lower levels of rainfall。that引导的是定语从句，修饰the areas;like意为“像......”，表举例;是现在分词作状语，表结果。
译文：这些区域现在是沙漠地区，像所有的干旱地区一样，对降雨量的变化周期极为敏感，结果导致其动植物的分布变化巨大且迅速。
杜月笙经典名言
美术课堂 3. The people who hunted the spar dert animals responded to drought by managing the wild resources they hunted and gathered, especially wild oxen, which had to have regular water supplies to survive.
分析：who引导的是定语从句，修饰people;they hunted and gathered这里是定语从句，省略了连接词that，修饰的是wild resources;which引导的是非限制性定语从句，修饰wild oxen。
