1.当心！车来了。 
    ____ ____!The train is coming.
2.吉姆经常在上课时向窗外看。 
   Jim often____ ____ ____ the window when he is in class.
3.半夜，外面传来了奇怪的声音。   
   _____ ____ ____ the night, there was a strange sound.
4.在公园野餐后，我们应该捡起垃圾。
   We should____ ____ ____ ____after we have a picnic in the park.
5.新年聚会结束了，让我们收拾教室吧。 
   The New Year's party is over. Let's____  ____the classroom.
6.女孩伸出一只手去摘那朵漂亮的花。