Complete the sentences. Fill in: am, is, are
1. Where is Ann? - In the living room. She ... arranging flowers in the vase.
2. Why ... William crying? - He can't find his ball.
3. What ... you doing? - Sh-sh! It's a surprise.
4. The children ... decorating the room for the New Year party. Will you help them?
5. Who ... singing? - My sister.