Answer:
1. The workers are building the road.
2. A sparrow is building it's nest in our letter box.
3. The spectators are watching a cricket match.
4. Sneha is reading a story book.
5. I am polishing my shoes.
Step-by-step explanation:
The present continuous is formed using am/is/are + present participle. Questions are indicated by inverting the subject and am/is/are. Negatives are made with not.