Answer:
Explanation:
In the upper thermosphere, atomic oxygen (O), atomic nitrogen (N), and helium (He) are the main components of air.
Yes indeed it is, I actually didn’t know that tho
Answer:
a. back muscles are strong to maintain erect posture.
Explanation:
Human back muscles are categorized as superficial, intermediate and deep muscles. The intrinsic (deep) back muscles of the human back regulate the movement of spine and maintain erect posture of human.
For example, the erector spinae is the largest muscle of the human back and is present on either side of spine. It consists of iliocostalis muscles (lateral), longissimus muscles (intermediate), and spinalis muscles. Together these muscles serve in extension of the spine and maintain the erect posture of the spine.
