Ans: waterfalls are most common where hanging valleys occur. Such valleys generally form when glacier ice deeply erodes a main or trunk valley, leaving tributary valleys literally hanging far above the main valley floor. After the glaciers have melted and withdrawn, streams from such tributary valleys must fall in order
Earthquakes occur when stress builds up in the Earth's crust and causes it to break in a line known as a fault. A fault is a crack in the Earth's crust caused by stress in the surrounding rocks.
Answer:
true is defined sustain development for first time
