过去进行时练习题
一、写出下列单词的现在分词：
Play___ sit___ buy___ begin___ take___ listen___
Sing___ swim___ put___ have___ see____ shop___
Stop___ dig____ run____
二、按要求改写句子
1. The boy was playing basketball.
否定句：____________________________
一般疑问句：_________________________
肯定回答：__________________________否定回答：______________________