Which would be a biotic factor in an ecosystem?

1)air
2)rain
3)algae

3

Explanation:

because biotic are things you can touch

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation:

20 drops hope this