一、Reading
The biggest and strongest animal on land is the elephant. The largest and heaviest animal in the sea is the whale. It's also the biggest eater in world. It eats a ton of food a day. It looks like a fish, but it is really a mammal. Although the elephant and the whale are both mammals, they are indeed very different.
二、解析
■ The biggest and strongest animal on land is the elephant.
- 定：The biggest and strongest
- 主：animal
- 地状：on land
- 系：is
- 表：the elephant.
■ The largest and heaviest animal in the sea is the whale.
- 定：The largest and heaviest
- 主：animal
- 地状：in the sea
- 系：is
- 表：the whale.
■ It's also the biggest eater in world.
- 主：It
- 系：is
- 状：also
- 定：the biggest
- 表：eater
- 地状：in world.
■ It eats a ton of food a day.
= It eats a ton of food every day.
- 主：It
- 谓：eats
- 定：a ton of
- 宾：food
- 时状：a day.
a day：此处的 a day = every day，前面有表数量的单位名词时，可用 a day 取代 every day.
■ It looks like a fish, but it is really a mammal.
- 主：It
- 系：looks
- 表：like a fish
- 并列连词：but
- 主：it
- 系：is
- 状：really
- 表：a mammal.
■ Although the elephant and the whale are both mammals, they are indeed very different.
- 让步状从：Although the the elephant and the whale are both mammals
- 引导词：Although
- 主：the elephant and the whale
- 系：are
- 定：both（of the）
- 表：mammals
- 主：they
- 系：are
- 状：indeed very
- 表：different.
although：副词连接词，引导状语从句，整个句子可视为副词修饰主句。
三、语法
all 和 both 的用法：
all：指三者或三者以上的人或物，用来代替或修饰可数名词；也可用来代替或修饰不可数名词。
both：指两个人或物，用来代替或修饰可数名词。
all 和 both 在句子中作主语、宾语、表语、定语等。如：
I know all of the four British students in their school.
(他们学校里四个英国学生我全认识)
Would you like this one or that one? –Both.
(你要这个还是那个？两个都要。)
all 和 both 既可以修饰名词（all / both + (the) + 名词)，也可以独立使用,采用“all/both + of the +名词(复数)”的形式，其中的 of 可以省略。如：All（of）（the）boys are naughty.(是男孩都调皮)