What statement is true about natural selection

Which worm has eyespots that are used to detect light? a fluke b marine worm c planarian d tapeworm

The more rapidly sedimentation occurs, the more likely it is that the remains will successfully form a fossil. as sedimentation continues, what happens to the amount of weight settling onto the organism? stays the same increases decreases cuts in half

What are positive impacts of algae? how is it used?