Correct sentence: The Arctic fox molts to stay warm and is white in winter and brown in summer.
Why this is better (step by step):
- Subject and verb: "The Arctic fox" is who we are talking about, and "molts" is the action it does.
- Purpose phrase: "to stay warm" sounds more natural than "to be warm." It tells why the fox molts.
- Clear color change: "is white in winter and brown in summer" shows both colors in a simple, parallel way.
Another easy way to write it:
- The Arctic fox molts to stay warm.
- It is white in winter and brown in summer.
Note: "Molts" means the fox sheds its fur and grows new fur, which helps it stay warm and change color.