What happens while humans
sleep?

Many biological processes happen during sleep: The brain stores new information and gets rid of toxic waste. Nerve cells communicate and reorganize, which supports healthy brain function. The body repairs cells, restores energy, and releases molecules like hormones and proteins.

When you sleep, your body undergoes a series of changes that enable the rest that is vital to your overall health. Sleep allows the brain and body to slow down and engage in processes of recovery, promoting better physical and mental performance the next day and over the long-term.

the answer is b. glad to .

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave