What do you think we need to do to help the lake ecosystem

By decreasing the emition of methane, so2(sulfur dioxide) and no2(nitrogen dioxide)

Explanation:

Decreasing the emition of this gases could prevent acidic rain. Preventing acidic rain makes the lake support life.

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.

the awnser is group 12