---It rains heavily this morning.Is everyone here today?---Yes.______of us is late for school.
We should pay more attention ______teenage problems.
______he was exercising at the park yesterday morning, he found a purse under the tree.
There is ______ university in the east of the city and ______ university is big and modern.
—Mom, this is my friend, David. — .
Let’s play ____ basketball.