Nitrification is electrophilic substitution, and the reaction activity depends on the density of electron cloud on benzene ring. The higher the electron cloud density, the higher the activity.

The hydrocarbon group pushes electrons, and the ortho-para position of benzene ring is activated in electrophilic reaction, so the overall electron cloud density on benzene ring increases, and the ortho-para position rises the highest. The more alkyl groups, the higher electrophilic substitution activity of benzene ring, but attention should be paid to steric hindrance, such as tert-butyl group.

Obviously, the conclusion of (1) can be drawn.

Carbonyl attracts electrons, and due to the -C*** yoke effect, the electron cloud density of benzene ring decreases and the electrophilic substitution activity decreases. Among all groups, nitro group has the largest passivation effect because of the sum of its -I and -C effects.

Halogen atoms -I interact with +C, but -I is greater than +C, +C activates ortho-para, and -I reduces the overall electron cloud density of benzene ring, resulting in passivation, but the electron cloud density of ortho-para is relatively high.

Acetanilide is a derivative of aniline. As we know, aniline is dispersed in benzene ring because the electron cloud on N atom activates benzene ring and is located in ortho-para position. The peptide bond between amino group and acetyl group forms a large π system, but due to the electron-withdrawing property of carbonyl group, the activation degree decreases, but the overall result is still moderate activation, which shows that (2)

(3) The above explanation is enough.