Listen! I hear some birds ___________ the tree.A. sing in B. singing in B. sing on D. singing on
—I often saw you____basketball during the summer holidays. —Yes, you are right. A. playing B. play C. to play
—The food here is very nice. Thank you for inviting me. — _____ I’m glad you enjoyed it.
He made up his mind to devote his life _____ pollution ______ happily.
The players are passing the football from one to _____ in the football field.
_____ great progress he has made! I really think it’s _____ great success.