一、Reading
Time is precious. Nobody can afford to waste time. Once time has gone by, it will never return. You can never turn the clock back. Time passes very quickly. In fact, people say time flies. Time and tide wait for no man. We should, therefore, make the best use of our time.
二、解析
■ Time is precious.
- 主：Time
- 系：is
- 表：precious.
■ Nobody can afford to waste time.
- 主：Nobody
- 谓：can afford
- 宾：to waste time.
- 虚词：to
- 谓：waste
- 宾：time.
afford：vt.负担得起，力足以...
注：使用该单词时，须与助动词 can/cannot 并用，其后宾语则可为名词或不定式短语。
can/cannot afford + to + 动词原型：负担得起/力足以...
can/cannot afford + 名词：负担得起/力足以...
■ Once time has gone by, it will never return.
= As soon as time has gone by, ...
- 条件状从：Once time has gone by,
- 时态：现在完成时
- 引：Once
- 主：time
- 谓：has gone by
- 时态：一般将来时
- 主：it
- 状：never
- 谓：will return.
go by = pass by：（时间等）过去
return：vi.回来，返回
■ You can never turn the clock back.
- 主：You
- 状：never
- 谓：can turn
- 宾：the clock back.
turn the clock back：将时钟倒转，即指让时光倒流
■ Time passes very quickly.
= Time passes（by）very quickly.
= Time goes by very quickly.
- 主：Time
- 谓：passes
- 方状：very quickly.
此处 by 为副词，用来强调动词 passes 和 goes。
■ In fact, people say time flies.
- 状：In fact,
- 主：people
- 谓：say
- 宾：time flies.
Time flies.：光阴似箭。（谚语）
■ Time and tide wait for no man.
- 主：Time and tide
- 谓：wait for
- 宾：no man.
■ We should, therefore, make the best use of our time.
- 状：therefore
- 主：We
- 谓：should make the best use of
- 宾：our time.
make the best use of...：充分利用...，由 make good use of... 转变而来。
三、语法
- 现在完成时在表示条件的状语从句中的用法。
以上语法详见教材讲解。