Question

select the word that means positioned from side to side. look at an animals pupil, which is the darkest part of its eye. is it round, as in humans? or is it a line? if its a line, what direction does it go? some animals, such as sheep and goats, have pupils with a horizontal line. their eyes pick up more light going from the left and right, allowing them to spot predators more easily. an animal whose pupil is a line going up and down, however, is probably a predator. scientists believe the vertical line helps predators focus on prey animals. yes, your cat is a predator.

Explanation:

The text defines the meaning of a word related to a side - to - side position. The word "horizontal" means positioned from side to side as described in the context of animal pupils.

Answer:

horizontal