Practice MCQs

Explanation: The skin is the largest organ of the human body.

Explanation: Diamond is the hardest known natural substance.

Explanation: Albert Einstein developed the theory of relativity.

Explanation: Light travels at approximately 300,000 kilometers per second in a vacuum.

Explanation: Nitrogen makes up about 78% of Earth's atmosphere.

Explanation: Water boils at 100 degrees Celsius at sea level.

Explanation: Plants absorb carbon dioxide for photosynthesis.

Explanation: The adult human body has 206 bones.

Explanation: Mitochondria produce energy (ATP) for the cell, hence called the powerhouse.

Explanation: Mars appears red due to iron oxide on its surface.