Answer:
Mantle
Explanation:
The second layer of the earth is just below the crust. It's called the mantle. The mantle is very thick: 1800 miles deep. The mantle is a little bit like a sandwich.
Answer:
answer is letter b ..........
I kind of think that's okay for a scientific observation on it's own, but I guess if I'm going by the pattern of the other answers I gave you, I'd make it more specific.
You can say anything to make it more specific (generally in science though, it's focused on what the experiment is about). So ideas that i think would work: something about the frequency of the chirp, how many times the bird chirped, the volume, the duration of the sound.
considering he surface area-to-volume ratio, what structure does surface area represent?
d.plasma membrane
