Ответ:
1. Now, they aren`t (are not). They are yellow, brown and gold.
2. Yes, they are. The trees are white in winter.
3. Yes, they are. There are flowers in summer.
4. No, they aren`t. There are four seasons in the year.
5. No, they aren`t. There are three months in autum.
6. Yes, we do. We celebrate the New Year in winter.
7. No, it isn`t (is not). My big holiday is in summer.