In a pond ecosystem, what generally happen over a long period of time?
A) The pond will fill in, grasses and trees will grow there
B) It will become deeper than a lake.
C)The water will become stagnant and everything in the pond will die.
B)The pond will become filled with fish.

C

Explanation:

Over time the pond accumulates nutrients. This enrichment process is called eutrophication. The addition of nutrients stimulates the growth of aquatic life. These organisms live and grow and die

the supermassive black hole is in the middle of the galaxy.

explanation:

okay now i don't know this but for the pints nothing else to say bye