There _________a pencil and two rulers in the pencil—box．

 There ____some milk and bread on the table. You can have them ______ breakfast.

 _____ were nice to me when I was in the United States.

—Does the old man know the museum very well? —No, this is the first time he __________ here.

 One-third of the area ________ covered with trees. About seventy percent of the trees _______ been planted recently.