Selected MCQ

Current Question
Which gas causes global warming?
  • A. Oxygen
  • B. Nitrogen
  • C. CO₂
  • D. Helium
Correct Answer: C
Explanation:
CO₂ traps heat.
Related Question 1
Which boundary causes earthquakes?
  • A. Divergent
  • B. Convergent
  • C. Transform
  • D. All
Correct Answer: D
Explanation:
All plate boundaries can generate earthquakes.
Related Question 2
Which force causes objects to fall?
  • A. Magnetic
  • B. Electric
  • C. Gravitational
  • D. Nuclear
Correct Answer: C
Explanation:
Gravity pulls objects toward Earth.
Related Question 3
Which gas causes acid rain?
  • A. CO₂
  • B. SO₂
  • C. O₂
  • D. N₂
Correct Answer: B
Explanation:
SO₂ forms sulfuric acid in atmosphere.
Related Question 4
Which phenomenon causes tides?
  • A. Solar radiation
  • B. Wind
  • C. Gravitational pull of moon
  • D. Earth rotation only
Correct Answer: C
Explanation:
Moon’s gravity drives tidal effects.
Related Question 5
A keystone species is one whose removal causes:
  • A. No measurable ecological change
  • B. A disproportionately large effect on community structure
  • C. Only a reduction in primary productivity
  • D. Immediate extinction of all species
Correct Answer: B
Explanation:
Keystone species have ecological impacts much larger than expected from their abundance.