Scientists are convinced the positive effect of laughter physical and mental health.
--Jack,you seem very happy.--____________Our class has won the relay-race
It is the third time that she has won the race, ______ has surprised us all.
We had a picnic last term and it was full of fun, so let's have________one this month.
—I think you should phone Jenny and say sorry to her.—________. It was her fault.
When you finish reading the book, you'll have______better understanding of________life.