10 Multiple Choice Questions (MCQs) What percentage of Earth's surface is covered by the hydrosphere? A) 30% B) 50% C) 70% D) 90% Answer: C) 70% Which of the following drives the formation of ocean waves? A) Temperature B) Wind C) Earthquake D) Salinity Answer: B) Wind What causes the periodic rise and fall of sea levels known as tides? A) Earth's Rotation B) Ocean Currents C) Gravitational Forces of the Sun and Moon D) Wind Patterns Answer: C) Gravitational Forces of the Sun and Moon Which ocean current is responsible for keeping European ports ice-free in winter? A) Labrador Current B) Canary Current C) Gulf Stream D) California Current Answer: C) Gulf Stream Which type of current flows from polar regions towards the equator? A) Warm Current B) Surface Current C) Deep Water Current D) Cold Current Answer: D) Cold Current The ...