练习材料：
[Day 1799 2019-08-30]
Lesson 37-4 The process of ageing 衰老过程
But these are not analogous to what happens when man ages. A run-down watch is
still a watch and can be rewound. An old watch, by contrast, becomes so worn and
unreliable that it eventually is not worth mending. But a watch could never repair itself-
---it does not consist of living parts, only of metal, which wears away by friction. We
could, at one time, repair ourselves----well enough, at least, to overcome all but the
most instantly fatal illnesses and accidents. Between twelve and eighty years we
gradually lose this power; an illness which at twelve would knock us over, at eighty can
knock us out, and into our grave. If we could stay as vigorous as we are at twelve, it
would take about 700 years for half of us to die, and another 700 for the survivors to be
reduced by half again.
任务配置：L0+L1+L4
知识笔记：
analogous adj. 相似的; 类似的;
rewound v. 重绕(磁带等); 倒带; 倒片;
knock us over 把我们打倒
knock us out 把我们赶出去
练习感悟：
