1. **What was unknown to scientists during Wegener’s time?**
- **Earth’s crust is made of plates that move.**
This concept of plate tectonics was not established until later, well after Wegener proposed his theory of continental drift.
2. **Which continents have coastlines and mountain ranges that match up?**
- **Africa and South America**
These two continents are known for their matching coastlines and geological features, supporting the idea of continental drift.
3. **What is the name of a supercontinent that was once made up of all of Earth’s current continents?**
- **Pangaea**
Pangaea is the name given to the supercontinent that existed during the late Paleozoic and early Mesozoic eras, which included most of the Earth's landmasses.