the是特指某种东西,或者独一无二的物体
a/an 是随便某个
例如：I want a rabbit.我想要一只兔子 任何一只都行
I want the rabbit.我想要/这那只兔子 指定的一只
短语
a book,a desk,a chair,a computer,a rabbit
the sea,the sun,the earth,the moon,the Great Wall of China
句子
I have a book about China ,but I do not like it ,but my friend likes the book .
What a clever boy you are!
There is a desk.
Life on a farm is a far cry from what I've been used to.
A dark sky overhangs the earth.
The apples on the tree are green.
The book is hers.
We are part of the Earth and it is part of us.
The moon goes round the earth.
The night sky is now gorgeous with billions of stars.
