Điền vào chỗ trống dạng đúng của động từ tube: am, is, are, was, were. 
Example:  I am a student now. 
1. The homework....................... Very difficult yesterday. 
2. The childern............................. in the park five minutes ago.
3.Nha Trang ............................... a beautiful place. 
4.I............................. Late for school yesterday?  
5.Where............................she yesterday? She.............. At home. 
6. We............................ Tired today.We .................... At the party lastnight. 
7.She............................ Unhappy because she doesn't have any friends in the city. 
8..............................you at home yesterday morning?