Look!They ( )(swim)用什么形式填空

问题描述:

Look!They ( )(swim)用什么形式填空

are swimming
有了look,显然是用现在进行时

答案;  are  swimming
look  是现在进行时的标志词,结构:主语+  am/  is/  are  +  现在分词
不明白的再问哟,请及时采纳,多谢!