C.imagine指没有充分证据或单凭某种模糊印象和感觉而设想、推断。它跟guess一样，都是缺乏证据的。其后可接名词、v-ing的复合宾语、从句，还可与as连用。如：We can hardly imagine life without electricity．我们简直无法想象没有电的生活会怎么样。
I can"t imagine you/your living alone in the small mountain village．我简直不能想象你竟然独自住在小山村里。
5.be about to，be ready to的辨析：这两个复合助动词都作“乐意”讲，但有区别：前者总是用于肯定结构，而后者则既可用于肯定结构又可用于否定结构。（注：美国英语往往把be not about to作“不愿意”讲。）
比较：James was about to pay the bill．詹姆斯乐意掏钱付帐。（与was ready to通用）
James was not ready to pay the bill．詹姆斯不乐意掏钱付账。（不说He was not about to pay the bill．）
6.if only，so long as作“只要”讲时的区别：A.这两个复合连词同义，都作“只要”讲，但不一定能通用：if only只能连接表达一时动作的从句（参见词条517和519），而as／so long as则限于连接含有“持续”意义或表达存在的从句（参见词条583）。
例如：If only I have any chance，I shall try again．只要有机会，我将再试它一下。（所连接的从句没有“持续”的含义）
So long as he remains reactionary，no revolutionary peoplewill take united action with him．只要他保持反动不变，就没有革命人民同他采取联合行动。（所连接的从句含有“持续”的含义）
So long as there are still many things which we don"t knowand in which we lack experience we must be good at learningfrom other countries"strong points．只要我们还有许多东西不懂或缺乏经验，我们就该向别的国家学习它们的长处。（所连接的从句中含有“存在”的意义）
B.其次，前者多少含有“怀疑”的意境色彩，而后者则没有这种意思。
比较：Betty will do the job well if only she works hard．只要贝蒂好好干，她是会把工作搞好的。（多少存有怀疑）
Betty will do the job well so long as she works hard．只要贝蒂好好干，她是会把工作搞好的。（未必有怀疑）
【教学设计示例】
Step I.Introduction：Show some pictures about pollution.
StepII.Fast reading：A.Search for answers：（Now，I"ll give you 2 minutes to find out the answers：1.what international organization has been mentioned in the text？
2.In China，what is becoming a serious problem？
B.Read again and answerT or F：1.If waste is poured into rivers or seas without being treated，what will happen？
2.How is dangerous waste uauslly dealt with？
3.What problems does throwing away rubbish cause in western countries？
4.What is the situation like in China？
5.What has been done for environmental protection？
Step III.Fill in blanks.
Dealing with waste
1.Waste must betreated＿so that it doesnot become a danger to life.（paragraph1）
2.When this river finally reaches the sea，it pollutes the ocean.（paragraph1）
3.Human waste is piped directly into the sea without being treated.（paragraph2）
4.It is now against the law to throw anything into the sea within 5 kilomnetres of land.（paragraph3）
5.They seek to reduce waste，protect the earth，the oceans and all forms of life in them.（paragraph5）
The throw-away society1.This causes many problems.（paragraph1）
2.This is a particular problem for large cities.（paragraph1）
3.InChina，rubbish，such as used plastic bags and boxes known as“whitepollution”。（paragraph1）
Step IV.Group work。（Divide the class into several groups and provide them with some topics of the text，such as：1）How do people pollute the Ocean？（based on the text，the Ss can add something.）
2）How do people protect the sea and stop the pollution？（based on the text，the Ss can add something.）
3）What are the problems in China？（based on the text，the Ss can add something.）
（Give them some minutes to prepare and say their opinions）
Step V.Languag points：1.break down与break upbreak down：“分解”，可指物理变化或化学变化，如：After many years，rocks broke down into dirt.（经过多年以后，岩石就分解成尘埃。）
Water can be broken down into hydrogen and oxygen.（水可以分解成氢和氧）
当表示“拆散”意思时，break down与break up通用。如：The old cars were broken down up for their parts.（旧汽车被拆散以取得其零部件。）
break up：“撞毁，解体”如：
The ship was breaking up on the rock.（船在礁石上撞毁。）
2.depend on：“取决于…““靠…决定”如：The price depends on quality.（价格取决于质量。）
3.without doing：通常在句中作方式状语。这里的动词-ing形式，可以是一般式，完成式，复合结构和被动语态等，表示“（某人）未做，未曾做，未经…，未被…”等意思。如：He was lucky；he escaped from the burning house without being injured.
Do you think we"ll get a seat without having to queue？
They went back to the hotel without speaking.
Step VI.Home work：
Search for more information by themselves about the enviormental problems in Beijing，China，the world and how to deal with them and what should we do in dailylife.The Ss will deliver their speech at the beginning of next class.
【教学设计示例】
StepI.Let the students deliver their speeches.
StepII.Fast reading and discuss：Discuss these questions in groups of four.
1 Is any pollution caused by waste in China？
2 Is too much waste thrown away in China？
3 What materials are recycled in China？
4 How many different things are reused in China？
5 Can you tell how paper is made and recycled after being used？You may use the pictures as a guide StepIII.Fill in blanks.
1.European countries are now making an active effort to reuse materials more than they used to。（paragraph1）
2.Materials are collected，sorted，treated and used again.（paragraph1）
3.In many cities in Europe rubbish is collected separately.（paragraph1）
4.However，no single country can save the environment alone.（the last paragraph）
StepIV.教师可自己选用教学建议中的词语辨析或语法：过去分词的用法StepV.Homework：
P 35：Exs3，4，5&P34：Exs2.
