All the students__________ to plant trees and there’s nobody in the classroom.
While _________, people sometimes can’t help buying something they don’t really need.
All the people were shocked by what the little girl ________ when she was cheated and sold to the mountain village.
Our teacher said to us that the earth _________ around the sun.
As soon as he comes back, I’ll tell him when __________ and see him. \
--- Do you know our town well?--- No, this is the first time I _______ here.