A. Oxygen
B. Nitrogen
C. Carbon dioxide
D. Helium
What is the smallest particle of an element?
A. Molecule
B. Atom
C. Cell
D. Electron
Which organ removes waste from human blood?
A. Liver
B. Kidneys
C. Lungs
D. Heart
What is the main source of energy for Earth?
A. Wind
B. Sun
C. Water
D. Coal
Which planet is known as the Red Planet?
A. Venus
B. Jupiter
C. Mars
D. Saturn
Which modern technology is used in artificial intelligence?
A. Steam engine
B. Typewriter
C. Machine learning
D. Telegraph
Which part of the brain controls thinking?
A. Cerebellum
B. Cerebrum
C. Medulla
D. Brain stem
What is the boiling point of water at sea level?
A. 90°C
B. 95°C
C. 100°C
D. 110°C
Which blood cells fight infections in the body?
A. Red blood cells
B. White blood cells
C. Platelets
D. Plasma
Which layer protects Earth from harmful UV rays?
A. Troposphere
B. Mesosphere
C. Ozone layer
D. Ionosphere