20 ! where are the youngest rocks in the earth's crust

#4.) describe the most likely weather conditions at indiana / ohio boarder. also could someone double check my other answers? i'd really appreciate it

What evidence does the writer give to support his argument about coral reefs? a) he speaks of the activities of coral polyps. b) he describes the composition of the great barrier reef. c) he emphasizes the ways in which coral reefs are fragile. d) he points out the ways that scientists do research on the reefs.

These are the abiotic factor or biotic factors that restricts the numbers, reproduction, or distribution of organisms.