Which two types of structures make up the earthworm's heart? a)specialized cells b)organ systems c)tissues d)organisms

Which element is used in photosynthesis found in atmosphere and fixed by bacteria?

How was the climate when the ambulocetus was alive

Will mark brainliest if correct/available! which of the following statements is true? all plants need flowers to sexually reproduce. sexually reproduced offspring are identical to their parents. fertilization always occurs inside the female's body. a body cell has twice the number of chromosomes as an egg cell.