Give the structures of the following compounds:
$(i)$ $4-$Nitropropiophenone
$(ii)$ $2-$Hydroxycyclopentanecarbaldehyde
$(iii)$ Phenyl acetaldehyde

(N/A) $(i)$ $4-$Nitropropiophenone: The structure consists of a benzene ring with a nitro group $(-NO_2)$ at the $4-$position and a propiophenone group $(-CO-CH_2-CH_3)$ at the $1-$position.
$(ii)$ $2-$Hydroxycyclopentanecarbaldehyde: The structure consists of a cyclopentane ring with a carbaldehyde group $(-CHO)$ at position $1$ and a hydroxyl group $(-OH)$ at position $2$.
$(iii)$ Phenyl acetaldehyde: The structure consists of a phenyl group $(-C_6H_5)$ attached to an acetaldehyde group $(-CH_2-CHO)$.