Answer: The gateway drug effect (alternatively, stepping-stone theory, escalation hypothesis, or progression hypothesis) is a comprehensive catchphrase for the often observed effect that the use of a psychoactive substance is coupled to an increased probability of the use of further substances.
Explanation:
Sebaceous glands produce a substance that moisturizes and protects the skin.Because it produces a substance called sebum. The sebum moisturizes the skin and form a protective layer from infections.