—Do you know the boy _______ Simon? —Yes, he’s my brother’s good friend.

 —Where’s your mother, Helen?—She_________ the flowers in the garden.

 —____ your sister know Tom?        —No, she ____.

—Someone is knocking at the door. Who ______ it be? —It ______ be Tom. He is still in the school.

Food safety is important. Rules _____ to stop people from food pollution.