Answer:
Explanation:
Because extrusive rocks cool quickly, they only have time to form very small crystals such as basalt or none at all. On the other hand, intrusive rocks grow larger crystals because they take longer to cool. Extrusive rocks are usually fine-grained or glassy while intrusive rocks are coarse-grained.
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 After the glaciers have melted and withdrawn, streams from such tributary valleys must fall in order
13,000 different types of work, from 1938 to the late 1990s..... i think