A train car is to a train, as a is to a polymer and a molecule is to

Which best describes red blood cells? a. they are colorless b. they protect against disease-carrying microorganisms c. they transport oxygen throughout the body d. they aid in blood clotting

The embryos of a bird, a reptile, and a mammal are similar in appearance. how does comparing the physical appearance of embryos of different species support the theory of evolution? a. it shows that these organisms share a common ancestor. b. it provides evidence that these organisms eat the same foods.c. it shows that these organisms share the same habitat.d. it provides evidence that these organisms suffered a genetic mutation.

Math focus 4. calculate a map has index contours at 250 m, 500 m, and 750 m. what is the contour interval?