一、Reading
It's busy day at the Wangs' house. Mr. Wang is fixing his bike. Mrs. Wang is writing a letter. Tina is reading a book. Tony is exercising.
Even the dog is busy. It's chasing a cat. The cat is running for its life.
The Wangs are busy, but they're having fun.
二、解析
■ It's busy day at the Wangs' house.
- 主：It
- 系：is
- 定：busy
- 表：day
- 地状：at the Wangs' house.
- 介：at
- 宾：the Wangs' house
此处的 it 是代词，用来代替“今天”、“此刻”，常用于“It is + 时间名词”的句子结构中。
■ Mr. Wang is fixing his bike.
- 时态：现在进行时
- 主：Mr. Wang
- 谓：is fixing
- 宾：his bike.
结构：
主语+ am / are / is + 现在分词。
■ Mrs. Wang is writing a letter.
- 时态：现在进行时。
- 主：Mrs. Wang
- 谓：is writing
- 宾：a letter.
不可用一般现在时，现在时表常态。
■ Tina is reading a book.
- 时态：现在进行时。
- 主：Tina
- 谓：is reading
- 宾：a book. vvcc
常看书：he reads books， 表常态。
■ Tony is exercising.
- 时态：现在进行时。
- 主：Tony
- 谓：is exercising
常态：Tony exercises everyday.
■ Even the dog is busy.
- 时态：现在进行时。
- 状：Even
- 主：the dog
- 系：is
- 表：busy.
What is the dog doing? 狗正在做什么？
even 是副词，表“甚至”。
■ It's chasing a cat.
- 时态：现在进行时。
- 主：It
- 谓：is chasing
- 宾：a cat.
it 指代上句 the dog.
■ The cat is running for its life.
- 时态：现在进行时。
- 主：The Wangs
- 谓：are having fun.
- 目状：for its life.
for：为了。
■ The Wangs are busy, but they're having fun.
- 主：The Wangs
- 系：is
- 表：busy.
- 时态：现在进行时。
- 主：The Wangs
- 谓：are having fun.
三、例句
What time is it? It is five.
What time is it by your watch?
it 指“此刻，现在”。