1/ The bookcase was too big to get down the stairs.
The bookcase wasn't .............................
2/ I don't intend to wait here.
I am ...............................
3/ No body helps him do the homework.
He does .............................
4/ There were some tress in the field in the past.
There used ...........................................
GIÚP MÌNH VỚI CÁC BẠN ƠI