How can volcanic eruptions cause the average temperature on the planet to drop?

the ash in the atmosphere blocks the sunlight.

ash insulates the earth.

volcanic ash is hot.

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.