Ответ:

1. We are in Year 4 now.

2. This was our new cooker.

3. My friends were at the circus yesterday.

4. Where were the children? — They were in the playground.

5. What was your favourite day? — It was Saturday.

6. It was rainy last weekend.

7. Look! She is making a sandcastle.

8. Was he at school yesterday? — No, he was not, and his sister was at home.

9. The women were swimming in the sea.

10. Ben, where were you? — I was watching TV in the living room.

Правило: was употребляется с I/he/she/it, were — с you/we/they. В предложениях о настоящем времени используются am/is/are.