三年级上册英语中常见的缩写和完全形式包括：

缩写:

I'm = I am

S's = is

VS = versus

Rd = road

St = street

Ave = Avenue

Pl = place

Stree = Street

Rd. = Road

Ctrl = control

won't = will not

aren't = are not

haven't = have not

can't = can not

it's = it is / it has

I'd like to = I would like to

you'd better = you had better

完全形式:

I am

It is

He is

She is

You are

We are

They are

Is not = isn't

Are not = aren't

Have not = haven't

Has not = hasn't

What is = what's

Where is = where's

My name is = my name's

That is = that's

Let us = let's

这些缩写和完全形式在三年级上册英语中经常使用，帮助学生们更简洁、更流畅地进行英语表达和书写。建议学生们熟练掌握这些缩写，以便在日常生活和学习中能够更高效地使用英语。