Why do some fossils of some extinct organisms have been found while others have not?

Why do you think the puppy litter was all dark-haired?

List two modern organisms that have pentameral symmetry

Im is in a crowd of people at the mall looking for his girlfriend tammy, who was supposed to meet him for dinner. jim realizes tammy is across the room as he catches a whiff of her overpowering perfume, 'paris #6'. which process explains why jim is able to smell the perfume?