6.lengthen ： v. 使延长，变长，延伸
派生词：length n. 长度， 长
I‘ll have to lengthen this skirt. 我得把这条裙子放长。
There is a plan to lengthen the three-year course to four years.
有计划要将这个三年制课程延长为四年。
7.neglect：v./n. 忽视，忽略
He neglected his studies， so he failed to pass the exam.
他忽视了学业，因此没能通过考试。
Don‘t neglect to lock the door when your leave. 离开时别忘了锁门。
He always neglects his own health. 他总是不注意自己的健康。
近义词：ignore v. 忽视，不顾（主要指故意忽视，不管）；
例：I said hello to her， but she ignored me completely.
我向她打招呼，她竟不理睬我。
I can‘t ignore his rudeness any longer. 我不能再无视他的粗鲁了。
8.expectation： n. 期待，预料
派生词：expect v. 期待，期望
The size of the loss was beyond all of our expectations.
损失的数目超出了我们所有人的预料。
There are widespread expectations that the UK will cut its interest rate.
人们普遍预测英国会降低利率。
词组：phrases
1.to approximate to： 大体是，近于，近似，与…接近
Your latest design approximates much more closely to what I understand the building to be like.
你的最新设计与我所想的那房子的模样接近得多了。
His description of the event approximated to the truth.
他对事件的描述接近事实。
2.resistance to： 对… 的阻力，抵制
There will be fierce resistance to these proposals.
这些提议将会遭到激烈的抵制。
She has little resistance to germs and so is often ill.
她对病菌缺乏抵抗力，因而经常生病。
II.重点句子讲解
Aging in European Countries
We have to realize how old， how very old， we are. Nations are classified as “aged” when they have 7 per cent or more of their people aged 65 or above， （1）and by about 1970 every one of the advanced countries had become like this .of the really ancient societies， with over 13 per cent above 65， all are in Northwestern Europe.（2）At the beginning of the I980‘s East Germany had 15.6 per cent， Austria， Sweden， West Germany and France had 13.4 per cent or above， and England and Wales 13.3 per cent. Scotland had 12.3 per cent. Northern Ireland 10.8 per cent and the United States 9.9 per cent. We know that we are getting even older， and that the nearer a society approximates to zero population growth， the older its population is likely to be - at least， for any future that concerns us now.（3）
（1）Nations are classified as “aged” when they have 7 percent or more of their people aged 65 or above.
当一个国家有7% 或更多的人到65岁以上时，这个国家就被列为老龄化国家之列。
本句中are classified as 是一个动词短语，意为“把…分类为”as 作主语补足语；
句中when 引导一个时间状语从句。above 在此句中的意思是“以上”。
（2）该句的正常语序为All of the really ancient societies， with over 13 percent above 65， are in Northwestern Europe.由于主语中心词all与谓语动词are 间隔太长，因此倒装以显得紧凑。with over 13 per cent above 65 ，“有13%以上的人超过65岁”
（3）主句we know 后边有两个由that 引导的宾语从句。
在第二个宾语从句中用了“越…就越”的结构。
To these now familiar facts a number of further facts may be added， some of them only recently recognized.（4）There is the apparent paradox that the effective cause of the high proportion of the old is births rather than deaths（5）There is the economic principle that the dependency ratio - the degree to which those who cannot earn depend for a living on those who can - is more advantageous in older societies like ours than in the younger societies of the developing world， because lots of dependent babies are more of a liability than numbers of the inactive aged.（6）There is the appreciation of the salient historical truth that the aging of advanced societies has been a sudden change.