The Percentage of Oxygen in the Earth's Crust Is ______,Whereas

question 66

Multiple Choice

The percentage of oxygen in the Earth's crust is ______,whereas that in the atmosphere is ________.

• A)10%;72%
• B)5%;50%
• C)27%;27%
• D)1.5%;86%
• E)46%;21%

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Definitions:

Melatonin

Melatonin is a hormone produced by the pineal gland that regulates sleep-wake cycles.

Psychoactive Drugs

Substances that can alter one's perception, mood, consciousness, cognition, or behavior by affecting brain function.

Euphoria

An intense state of happiness and well-being, sometimes beyond what is normally experienced.

E-Cigarettes

Battery-operated devices that deliver nicotine with flavorings and other chemicals to the user in vapor instead of smoke.