Original sentence: Mountains are huge folds in the Earth's rocky coat that rose and froze forever.
Better sentences:
- Mountains are huge folds in the Earth's rocky crust.
- Mountains are huge folds in the Earth's rocky crust that rose and have stayed that way ever since.
Why these are better (easy steps):
- "Rocky crust" is a clearer phrase than "rocky coat." Scientists call the outer layer the Earth’s "crust."
- "Froze" usually means turned into ice. That makes the sentence confusing. If you mean they stopped changing, say "have stayed that way" or "remained."
- Using "have stayed" shows they rose in the past and are still there now.
Short kid-friendly meaning: Mountains formed when Earth's rock got pushed up, and they have stayed standing for a very long time.