6. .Pollution is caused either by man’s release of completely new and often artificial substances into the environment，or by releasing greatly increased amounts of a natural substance，such as oil from oil tankers into the sea.引起污染有两种途径：一是人们经常把全新的人造物质释放到环境中，或是把大量的天然物质譬如油轮溢出的石油释放到海里。（此句为简单句，主要是由两个 by引出的短语把这个句变得复杂了。第一个into是名词~ease要求的。第二个into是动名词releasing要求的。From oil tankers作定语修饰oil.）
7. Hardening of grey cast iron may be carried out by heating the casting to above the critical range and then cooling it，usually in oil.灰口铸铁的淬火过程是：先把铸铁加热到临界温度以上，然后加以冷却，通常在油里冷却。（heating.……to above，“把……加热到……之上”。to above是双重介词。）不要想当然地想成是灰口铸铁的硬化。
8. Motion in the most general sense，conceived as the mode of existence，the inherent attribute，of matter，comprehends a11 changes and processes occurring in the universe，from mere change of place right up to thinking. 从最普遍的意义上来看，可以认为运动是物质存在的形式，是物质的固有属性，运动包括宇宙中所发生的一切变化和过程，从单纯位置的变化直到思维。（主语是motion，谓语是comprehends，被一个介词短语in the most general sense和一个分词短语conceived as……隔开了。of matter既说明existence，也说明attribute.介词短语from.……用来说明a11 changes and processes.）
9. Weather is a product of many pLysical factors operating in and on the troposphere with the principal ones being the unequal heating of the earth’s surface by the sun and the rather rapid rotation of the planet on its axis.天气是许多自然因素在对流层中起作用并对其施加影响的结果，其中太阳对地球表面加热不均等和地球自转比较快则是主要的因素。（with引导的复合结构作定语，用来修饰factors，ones代替factors.）
10. It is the village which suffers most，for it is not easy to break the traditional bonds uniting agriculturist families to families of craftsmen，nor to dispel the idea that some one who follows the traditional calling of this caste is acting in a more“suitable” way than some one who takes up a different occupation.乡村受害最大，因为从事农业家庭与从事手工业家庭的传统结合是很难分割的。此外，一些人认为一个人遵照等级制度的传统职业来办事要比从事不同的职业更为“合适”，这种想法也很难去掉。 （his.……which为强调句型，强调主语the village.原句是简单句，The village suffers most. for是连词，“因为”。uniting.……to，“把……与……连接”，是分词短语作定语修饰bonds. nor连词，连接两个并列成分，把to break.……和to dispel.……两个不定式短语连接起来。that.……occupation为同位语从句，用来揭示idea的概念内涵。calling意为“职业”，与occupation相呼应。 In a.……way，“以……方式”。）
