At the age of 12 years, the human body is at its most vigorous.

at one’s + 形容词最高级 ^{处于某人最…的状态}

• When are you at your best / worst / most effective / most vulnerable?
• The garden is at its most beautiful in June.
• Caesar was at his most powerful when he conquered Gaul.
• The garden is at its most beautiful in early spring. ^{花园在早春时节处于它最美的状态。}
• The garden is at its most vigorous in the spring.^{花园在春天处于最旺盛的状态。}
• The economy was at its most vigorous right before the downturn.^{经济在低迷期前正处于最旺盛的状态。}

at + 最高级

be + on + 状态名词 ^{（表状态会持续）}

• He was constantly on the move.
• He is always on the go.
• The patient is on the recovery.
• The program is on the air at 7 o’clock.
• Crimes are on the rise.
• The dog is on the alert.
• The workers are on strike.
• Today I’m on duty.
• The nurse is on call.
• I’m here on business / vacation.

under + 状态名词 ^{(处于某种状态)}

• The car is under repair.
• The castle is under attack.
• The subject is under discussion.
• The matter is under consideration.
• You are under arrest.
• The patient is under observation.
• The case is under investigation.
• The bridge is under construction.
• The building is under renovation.

It has yet to reach its full size and strength, and its owner (has yet to reach) his or her full intelligence; but at this age the likelihood of death is least.

has yet to do ^{尚未 .../还没有...;还没有…；有待于…}

•  I have yet to make a decision.
• The bank has yet to respond to our letter.
• The Da Vinci Code, starring Tom Hanks, has yet to open next month.
• The committee has yet to reach a final decision on the proposal.^{委员会尚未就该提案做出最终决定。}
• The new technology has yet to fully realize its potential.^{这项新技术尚未完全实现其潜力。}

have only to do … to do ^{…只需……就可以……}

… and we have only to turn to that extraordinary discovery of echo-location in bats to see a case in which the voice plays a strictly utilitarian role.

• You have only to press the button to call the nurse.

并列句的省略

… and its owner (has yet to reach) his or her full intelligence.

• Spiders are not insects, as many people think, nor (are they) even nearly related to them.
• Such inns as there were were generally dirty and flea-ridden; the food (was) simply local cheese accompanied by bread often twelve months old, all washed down with coarse wine.
• During these tests she was able to read a newspaper through an opaque screen and, stranger still, by moving her elbow over a child's game of Lotto she was able to describe the figures and colours printed on it; and, in another instance, wearing stockings and slippers, (she was able) to make out with her foot the outlines and colours of a picture hidden under a carpet.
• But, if this world is not merely a bad joke, life (is not merely) a vulgar flare amid the cool radiance of the stars, and existence (is not merely) an empty laugh braying across the mysteries; …

It is said that in England death is pressing, in Canada (death is) inevitable and in California (death is) optional. Small wonder. Americans’ life expectancy has nearly doubled over the past century. Failing hips can be replaced, clinical depression (can be) controlled, cataracts (can be) removed in a 30-minutes surgical procedure.

最高级可省略 the 的情况

• Vegetables are best when they are fresh.
• We are busiest on Mondays.

… but at this age the possibilities of death are fewest. ^课文替换

Earlier, we were infants and young children, and consequently more vulnerable; later, we shall undergo a progressive loss of our vigour and resistance which, though (the loss is) imperceptible at first, (it) will finally become so steep that we can live no longer, however well we look after ourselves, and however well society, and our doctors, look after us.

并列句的省略

• Earlier, we were infants and young children, and (we were) consequentlymore vulnerable;
• … though (the loss is) imperceptible at first, … ^{从句里的省略}

undergo ^{v.经历，经受}

• Although mankind has undergone no general improvement in intelligence or morality, …
• Fans may undergo body searches by security guards. ^{仰慕者们可能要接受保安人员的搜身。}
• Some children undergo a complete transformation when they become teenagers. ^{一些儿童进入少年期会完全变成另一个人。}
• The old buildings will undergo a progressive renovation over the next decade.^{这些旧建筑将在未来十年内经历逐步翻新。}
• The patient will undergo a series of medical tests before the surgery.^{患者在手术前将接受一系列的医学检查。}

progressive ^{adj.进步的，先进的；逐步发生的}

• One prominent symptom of the disease is progressive loss of memory.
• The reactionary policemen broke and arrested many progressive students. ^{反动警察打垮并逮捕了许多激进学生。}
• Have a "progressive" dinner together.^{共进一次“循序渐进的”晚餐。}

This decline in vigour with the passing of time is called ageing.

decline in ^{...的衰退/下降(注意介词用in)}

• The team showed a noticeable decline in vigour during the second half of the game.^{球队在比赛的下半场表现出明显的活力下降。}
• The doctor noted a gradual decline in the patient's physical vigour.^{医生注意到患者体力的逐渐衰退。}
• There will be an increase in the range of 0 to 3 per cent. ^{将会有0到3个百分点的增长幅度。}

It is one of the most unpleasant discoveries which we all make that we must decline in this way, that if we escape wars, accidents and diseases we shall eventually 'die of old age', and that this happens at a rate which differs little from person to person, so that there are heavy odds in favour of our dying between the ages of 65 and 80.

decline ^{v. deteriorate （健康、品质等）恶化；衰退}

• His health has been declining / deteriorating progressively for several months.
• The patient's condition began to decline rapidly after the surgery. ^{手术后，病人的情况开始迅速恶化。}
• The weather continued to deteriorate throughout the afternoon. ^{整个下午天气都在持续恶化。}

“ if ”引导让步状语从句 1、= even if …

• If he noticed the fact, he didn’t care.
• … even their sagas, if they had any, are forgotten.
• This result merely confirms earlier American and British studies: if there is any effect of noise upon mental health, it must be so small that present methods of psychiatric diagnosis cannot find it.

differ little ^{几乎没有区别(hardly)}

• The two versions of the document differ little in their core arguments. ^{这两版文件的核心观点几乎没有区别。}

from person to person ^{人际之间（form ... to ... 零冠词）}

• The need for sleep varies considerably from person to person. ^{不同的人对睡眠的需要差异相当大。}
• The symptoms of the common cold differ little from person to person.^{普通感冒的症状人与人之间差别不大。}
• The average response time differs little from person to person in this test.^{在这项测试中，平均反应时间人与人之间差别不大。}

There are heavy / overwhelming odds in favor of / against … ^很可能...

• The team had heavy odds in favour of winning the championship this year.^{该队今年赢得冠军的可能性非常大。}
• Given the success of the pilot program, there are heavy odds in favour of the full rollout.^{鉴于试点项目的成功，全面推广的可能性非常大。}

life expectancy ^{人口预期寿命}

• Prevention of heart disease and stroke will increase life expectancy.^{对心脏病和中风的预防将延长预期寿命。}
• The life expectancy for men in Harlem was less than that of men in Bangladesh. ^{哈莱姆区男性的预期寿命低于孟加拉国男性。}
• Scientists estimate that smoking reduces life expectancy by around 2 years on average. ^{科学家们估计，吸烟使预期寿命平均缩短了大约两年时间。}

die of old age ^{死于年老/老死}

• The great artist finally died of old age in his sleep.^{这位伟大的艺术家最终在睡梦中老死。}
• In a healthy society, most people should expect to die of old age.^{在一个健康的社会里，大多数人应该期望老死。}

Some of us will die sooner, a few will live longer -- on into a ninth or tenth decade.

on into a... decade ^{持续到…的十年/进入…的十年}

• The author continued writing on into his eighth decade.^{这位作者持续写作直到他八十多岁。}
• The ancient tradition has continued on into the third millennium.^{这个古老的传统已经持续到第三个千年。}

But the chances are against it, and there is a virtual limit on how long we can hope to remain alive, however lucky and robust we are.

the chances are against it ^{可能性很小/机会渺茫}

• The following day, however, the doctor consoled him by telling him that his chances of being able to leave hospital in time for new year celebrations were good.
• As she is not rich, the chances that she will ever be able to afford such purchases are remote; but she is never sufficiently strong-minded to be able to stop the practice.
• She is still hoping for a promotion, but the chances are against it this year.^{她仍在希望升职，但今年机会渺茫。}
• They tried to fix the old machine, but the chances were against it working again.^{他们试图修理这台旧机器，但它再次工作的可能性很小。}

virtual limit on... ^{对…的实际限制}

• There is a virtual limit on how fast we can run.
• There is a virtual restriction on the rate of economic growth in a specific country.
• There are strict limits / restrictions on presidential power.
• The budget imposed a virtual limit on the number of staff they could hire.^{预算对他们可以雇佣的员工数量施加了实际的限制。}
• Currently, there is a virtual limit on the number of participants allowed in the hall. ^{目前，大厅里允许的人数受到了实质性的限制。}