g kites, ______ some researchers point out, can not only bring about joy to us, but also promote our physical and mental health.

The teacher asks us not to _______ the garden in class .

The car factory has developed several new types of cars, which _________ people of different ages.

________do you visit your grandparents in the countryside —Once a week.

The old father ______ the project ten years ago but didn’t live long enough to complete it sohis sons and daughters ______ and are continuing doing it now.