According to the $IUPAC$ system,the given compound is named as:

Fill in the blanks:
$(1)$ The $IUPAC$ name of $CH_3COCH_2CH_2CH_2COOH$ is .........
$(2)$ The formula of pent$-4-$en$-2-$ol is .........
$(3)$ The $IUPAC$ name of the following structure is ......... and ......... is the main functional group in it.
(Structure: $A$ cyclohexene ring with an $-OH$ group attached to the carbon adjacent to the double bond,such that the double bond is between carbons $2$ and $3$ relative to the $-OH$ at position $1$.)
$(4)$ For $CH_3CH(OH)CH_2CH_2CH_2CHO$,the main functional group and the second priority group are ......... and ......... respectively.

Provide the $IUPAC$ name and identify the functional group for each of the following compounds:
$(i)$ $CH_3SO_3H$
$(ii)$ $CH_3CH_2CH_2NO_2$
$(iii)$ $CH_3CH_2CH_2CH_2CONH_2$
$(iv)$ $CH_3CH_2CH_2CH(NH_2)CH_3$

Provide the number of carbon atoms and their corresponding prefixes for naming alkanes.

The $IUPAC$ name of $CH_3CH_2CH(C_2H_5)COOCH_3$ is

What is the $IUPAC$ name of the given compound?