Humans can digest starch but not cellulose because?

Amale bird-of-paradise uses a dance to attract mates in which it flaps its tail feathers on the ground and jumps around a potential female mate. a different male bird-of-paradise does a similar dance but it jumps around the female in the opposite direction. the female bird is only attracted to one style of dance, in one direction. this is an example of speciation.

9. what area of study applies scientific findings to create ways for solving problems or improving life? a biogeology b mathematics c manufacturing d engineering

Can nonrenewable resources be used sustainably?