Water boils at what temperature at sea level?
A. 90°C
B. 80°C
C. 100°F
D. 100°C
The basic unit of life is:
A. Atom
B. Cell
C. Molecule
D. Tissue
Which gas is commonly used in fire extinguishers?
A. Oxygen
B. Hydrogen
C. Carbon dioxide
D. Nitrogen
The hardest natural substance on Earth is:
A. Gold
B. Iron
C. Diamond
D. Quartz
The type of blood in arteries is usually:
A. Blue
B. Oxygenated
C. Deoxygenated
D. Mixed
The Earth revolves around the Sun in approximately:
A. 24 hours
B. 30 days
C. 365 days
D. 365 days
Which part of the plant conducts photosynthesis?
A. Root
B. Stem
C. Leaf
D. Flower
Which force keeps planets in orbit around the Sun?
A. Magnetic force
B. Gravitational force
C. Friction
D. Centrifugal force
The boiling point of water decreases with:
A. Decreased temperature
B. Increased altitude
C. Decreased humidity
D. Increased pressure
The largest organ of the human body is:
A. Liver
B. Heart
C. Skin
D. Lungs