________ is the consistent, unbroken tracking by the eyes that serves to maintain focus on a moving visual target

What is the releasing stimulus for the threat display exhibited by male stickleback fish when intruding males enter their territory?

a) flaring of the gills b) greenish-blue tail fin c) red spot on the belly d) fanned-out display of fins

While the sanguine humor was considered __________, the phlegmatic was considered __________

A) cheerful; apathetic B) slow; quick C) apathetic; hopeful D) depressed; apathetic E) angry; depressed