Why do astronomers use astronomical units (AU) instead of kilometers (km)?(1 point) A There are no km in outer space, only AU.

B AU is used in astronomy, while km is used in physics.

C Large distances are easier to express in AU than in km.

D AU is used for spacing, while km is used for length.

Covalent bonds are formed between metals and boiling points true or false

Hector is back from his morning run and is feeling light-headed because his energy is depleted which food item will provide him with a quick source of carbohydrates

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.