83. My teacher has eyes in the back of her
head.
A. Idiom
B. Metaphor
C. Simile
D. Personification
E. Onomatopoeia
84 Her hair was like gravy running brown off

i think the answer is simile

A. Idiom.“Eyes in the back of her head” is an idiom, as it is a figurative (non-literal) English expression, the meaning of which is not easily discernible from the decoding of the phrase itself; it requires outside knowledge of the language, and so would likely be puzzling to a non-native speaker.