the+序数词+最高级+名词单数

…the +序数词+最高级+单数名词+in+范围… 意为在某范围内是第几…的

例句：

Canada is the second largest country in the world.

The Yellow River is the second longest river in China .

Chang jiang river is the first longest river in our country.长江是我国最长的河流.

其它用法：

(1)Which (who)… (the+)最高级，A， B or C? 意为A ，B，C哪个最…?

Which is the biggest? The sun， the earth， the moon?

哪个是最大的? 太阳，地球，月亮?

Who runs (the) fastest? Jim ，Mary or me?

谁跑的最快?吉姆，玛丽还是我?

(2) A…+the+最高级+(that) I have ever seen/heard/read 意为A是我见过(听过，读过)最…的.

You are the most beautiful girl(that) I have ever seen.你是我见过最漂亮的女孩.

Harry is the most interesting book (that) I have ever read.哈利是我读过最有趣的书.

He works the hardest that I have never seen before他是我见过工作最努力的人.