Potential entrants are more likely to be deterred from actually entering an industry when

incumbent firms are willing and able to be aggressive in defending their market positions against entry.

a. suckling by young

b. hypothalamus

c. dopamine

d. trh

e. anterior pituitary

f. mammary glands

g. milk production

on island x the species needed to adapt because they were being subject to predators which didn't inhabit island y.