Answer:
HS(-)
HCOO(-)
SO3(2-)
SO4(2-)
S(2-)
NO2(-)
CN(-)
Explanation:
The parenthesis are the charges of the compounds. When an acid is introduced in a base, it dissociates its Hydrogens giving protons to the base. In this case, if you remove one hydrogen of a compound, you will reduce the charge of a compound since basically you're removing a positive charge from a compound. If you need to, I can explain how the thing of the charges work.
In fact, the definition of a conjugate base is a compound created when the original (an acid) compound dissacioate an atom of hydrogen (a proton) in a base.