HELP please I really don’t understand this!

Monkeys and bats have similar bone structure in their forelimbs. however, monkeys have longer forelimbs to use for climbing and swinging in trees. bats have shorter forelimbs to use for flight. which term best describes how monkey and bat forelimbs are related to each other? a. homologous b. embryonic c. analogous d. vestigial

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it

Which change to the system wood cause the freely-moving piston to lower?