There  three pens on the desk.（ ）

A．have

B．are

C．is

Mother Duck  three eggs. (   )

A．has

B．have

C．is

用单词的适当形式填空。
have   sit be    look    open
（1）There ________three small eggs and a big egg.   
（2）Mother Duck________on the eggs.   
（3）The big egg________later.   
（4）It is winter. It is cold. The ugly duckling________no home.   
（5）The ugly duckling________into the water. He is a beautiful swan.