Answer: 1)
2) 
3) 
4) 
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.
1) 
Here,
is loosing a proton, thus it is considered as an acid and after losing a proton, it forms
which is a conjugate base.
2) 
Here,
is loosing a proton, thus it is considered as an acid and after losing a proton, it forms
which is a conjugate base.
3) 
Here,
is loosing a proton, thus it is considered as an acid and after losing a proton, it forms
which is a conjugate base.
4) 
Here,
is loosing a proton, thus it is considered as an acid and after losing a proton, it forms
which is a conjugate base.