Answer:
the inner core, outer core, mantel, and the crust
Explanation:
these are the 4 layers of the earth
Heres a few examples:
-washing your hands
-use of protective equipment like, gloves, masks, and eyeglasses.
-coughing in your arm
-sneezing into a tissue
-using sterile instruments and devices.
Answer:
The states of arousal describe the cycle of sleeping and alertness.
Explanation: