| A | B |
|---|
| visible | able to be seen |
| valley | An area of low land between hills or mountains, often with a river running through it |
| rise | To move upwards |
| public | All ordinary people |
| liquid | Not solid or gas and that can be poured easily |
| formation | The development of something into a particular thing or shape |
| fairly | more than average, but less than very |
| erosion | Slow reduction or destruction |
| defence | (A) protection or support against attack, criticism or infection |
| collide | to hit something or someone that is moving in a different direction from you |
| ruined | Destroyed or spoilt |
| estimate | To guess the cost, size, value, etc. of something |
| constantly | all the time, frequently |
| controversial | causing disagreement or discussion |
| float | To stay on the surface of a liquid and not sink |
