Answer:
A the answer is A I'm sure
Answer:
Depends, but in most cases, 2.
It's best to use as many digits as possible to keep it accurate.
Explanation:
This varies between teachers, as most schools go with 2 decimal places.
This is something that depends in your situation.
You technically want as many decimals as possible to keep it as accurate, but most people stick with 2.
I personally do 3, and commonly do 5 sometimes.
Answer:
Water
Explanation:
Because water is very important
Animals and Plants won't have a place to live, get food and resourses. Some organisms won't have anyshelter, because some live in the water.
Answer:
: conjugate acid of 
: conjugate base of 
: conjugate base of 
: conjugate acid of 
Explanation:
According to the Bronsted-Lowry conjugate acid-base theory, an acid is defined as a substance which looses donates protons and thus forming conjugate base and a base is defined as a substance which accepts protons and thus forming conjugate acid.

Here in forward reaction
is accepting a proton, thus it is considered as a base and after accepting a proton, it forms
which is a conjugate acid.
And
is losing a proton, thus it is considered as an acid and after loosing a proton, it forms
which is a conjugate base.
Similarly in the backward reaction,
is loosing a proton, thus it is considered as a acid and after loosing a proton, it forms
which is a conjugate base.
And
is accepting a proton, thus it is considered as a base and after accepting a proton, it forms
which is a conjugate acid.