阅读短文，从方框中选择恰当的词语并用其适当形式填空，使短文完整、通顺。每个限用一次，其中有两个是多余的。

because，crowded，they, stop，wear, imagine， understand，into，wait for, find，if，home

    Early one Saturday morning，Ann brought her son Sam to her friends Bill and Kate．Ann asked  to look after him for the day．Sam，a boy of six years old，had black hair and was a pair of jeans and a bright yellow shirt．
At eleven o'clock, Bill took Sam town．Sam walked along behind Bill，looking at the windows of all the shops they passed．After lunch they went to a park．The park was very ．Bill stopped to buy some chocolate．When he turned around to give some to Sam，the boy wasn't there．Bill ran around calling Sam，but he couldn't  him．About an hour later, just m front of a shop．he saw the black hair, the pair of jeans and the bright yellow shirt．It looked as矿(好像)the boy was someone to come out of the shop．it was quite late，Bill ran across the road．took the boy by the hand and hurried off(匆匆
离去)．The boy began to shout and cry, but Bill couldn't a word the boy was saying．All the way back the boy made a lot of noise．
When they got at last，Bill went straight to the kitchen，with the boy still crying．At the door Bill in amazement(惊愕地)．There，sitting at the kitchen table with Kate，was a small boy with black hair, in a pair of jeans and a  bright yellow shirt．