Answer:
Here's what i think.
Explanation:
Tides can be extremely dangerous, in some places, high tide will flood caves which people otherwise wouldn't notice as flood-able. Knowing the tides can save lives of Spelunkers (people who explore caves). Another example is sailing. The tides can be important because tide can determine if your boat will be smashed against rocks, or if it is safe to dock!
Carbon (C) is an element
Carbon Dioxide (CO2) is a compound
Hydrogen (H) is an element
Sodium Chloride (NaCl) is a compound
A good way to tell whether something is a compound or an element, is that in a compound there is a mixture of different elements. Like in Carbon Dioxide, the symbol is CO2. This shows the carbon (C) and oxygen (O) together. I hope i worded that well enough and this helps :)
I think the answer is nitrogen fixation.
2 abiotic(non living) limiting factors are water(A) and food(B)
