5. How would living in an estuary help crabs avoid the problems that carbonic acid creates?
Please help

Carbon dioxide dissolve readily in sea water hence makes it high in carbonic acid concentration. The fresh water will dilute the concentration of carbonic acid thus preventing the crab from being exposed to high concentrations which can dissolve its shell.

Hope this helps !

1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.