What ecosystem is being described in the passage?
A) lake
B) ocean
C) estuary
D) tropical forest

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

Last week i was assigned a thematic. we have groups of three but the people i was assigned with haven't been in school for days. i would appreciate if anyone can me with my thematic . i highlighted most of the important steps and i circled my thematic topic. in desperate need : ( its due on february 19

Sequence how oxygen accumulated in the atmosphere and the effect it had on life by completing the flowchart