as  

They were alldressed as clowns.

She works as a shop assistant/doctor.

You can use thatglass as a vase.

as..as

Shedoesn't play basketball as wellas her sister.

（she doesn't play basketball as well as hersister does）

Hedoesn't earn as much as me.  

He doesn't earn asmuch as I do.

Eat asmuch as you like.

Run as fast as youcan.

the exam is not as difficult as last time

The exam is not as difficult as that of last time.

as soon/quick/early as possible (as you can)

The baby can cry as soon as he is born.

Pleasecome as soon/early as possible (as you can)

As many as 300  new books were needed this year.