—Yes, in the 1990s.
—Yes, it will be more beautiful if more trees and grass _____ by us.
— Well, I to be a volunteer for the Tree Planting Day.
—No, it___________. That's one of the school rules.
—Nothing _____ without hard work. It took much effort for Quan to learn skills.
—No, neither of us________.
—Good idea! I'm sure the hill _______with green trees in a few years.