The $IUPAC$ name of the following structure $(CH_3)_3C-C\equiv C-CH(CH_3)_2$ is:

Fill in the blanks:
$(1)$ The $IUPAC$ names of $CH_3COOCH_3$ and $CH_3CH_2COOCH_3$ are ....... and ....... respectively.
$(2)$ ....... isomers of dibromobenzene exist.
$(3)$ ........ is the $IUPAC$ name and ........... is the common name of $C_6H_5OCH_3$ respectively.
$(4)$ The structure of $1-$chloro$-2,4-$dinitrobenzene is shown below.

Select the correct $IUPAC$ name of pyrogallol.

The correct $IUPAC$ name for the given structure is:

Give $IUPAC$ names of the following compounds:
$(i)$ $CH_3-CH(Cl)-CH(CH_3)-CH(CH_3)-CH_2OH$
$(ii)$ $CH_3-CH(OCH_2CH_3)-CH_3$
$(iii)$ Structure of $2,6-$dimethylphenol
$(iv)$ Structure of $1-$ethoxy$-2-$nitrocyclohexane

What is the $IUPAC$ name of $CH_3CH = C(COOH)CH_2CH_3$?