Answer:
defines the problem to be explored
Answer:
Aquatic ecosystems include oceans, lakes, rivers, streams, estuaries, and wetlands. Within these aquatic ecosystems are living things that depend on the water for survival, such as fish, plants, and microorganisms. These ecosystems are very fragile and can be easily disturbed by pollution.
Explanation:
Answer:
and the other questions you have the arm to
The first and last sounds most reasonable, but I will go with the last one.
Calcium carbonate or silica