Population growth in the united states is due mainly to
a. increased birth rate b. increased life expectancy c. immigration d. emigration

silty loam

hope this

since there are no options posted i'll give you a few examples.

a dolphin's flipper, bird's wing, cat's leg.

idk let me see fdfdgdg

i believe it's c. the trait for large beaks will be passed on to future generations through natural selection.

since eventually smaller beaks would have to find another source of food or even eventually just die out from the lack of food.