Continents & Oceans — Set 6

Correct Answer: A. Seven

• **Seven continents** = the globally accepted model: Asia, Africa, North America, South America, Antarctica, Europe, and Australia/Oceania. • **Alternative models** — some cultures combine Europe and Asia as Eurasia (6-continent model) or use other groupings; the 7-continent model is standard in English-speaking countries. • 💡 Wrong-option analysis: Six: some models combine Europe+Asia (Eurasia) or the Americas, but standard is seven; Eight: no standard model uses eight continents; Five: one model merges Americas and Eurasia into two, but that is non-standard.

Correct Answer: D. Asia

• **Asia** = world's largest continent by land area, covering about 30% of Earth's total land surface — approximately 44.5 million sq km. • **Most populous** — Asia also has the most people (over 4.5 billion); it is bordered by the Arctic, Pacific, and Indian Oceans on three sides. • 💡 Wrong-option analysis: Africa: second-largest continent, about 30.3 million sq km; North America: third-largest, about 24.7 million sq km; Antarctica: fifth-largest, about 14 million sq km (without ice).

Correct Answer: C. Australia

• **Australia** = the world's smallest continent by land area, approximately 7.7 million sq km — about the size of the contiguous United States. • **Island continent** — Australia's geographic isolation for millions of years led to unique endemic species (kangaroos, koalas, platypus); it is also the only continent that is one country. • 💡 Wrong-option analysis: Antarctica: larger than Australia (~14 million sq km), so not the smallest; South America: much larger, ~17.8 million sq km; Europe: approximately 10.5 million sq km, larger than Australia.

Correct Answer: C. Pacific Ocean

• **Pacific Ocean** = the world's largest and deepest ocean, covering about one-third of Earth's surface — more than all continents combined. • **Named Pacific** — Ferdinand Magellan named it Mar Pacifico (peaceful sea) in 1520 after emerging from the stormy Strait of Magellan; it contains the Mariana Trench (deepest point). • 💡 Wrong-option analysis: Atlantic Ocean: second-largest, about half the size of Pacific; Indian Ocean: third-largest; Arctic Ocean: smallest of the five.

Correct Answer: D. Atlantic Ocean

• **Atlantic Ocean** = the second-largest ocean, covering about 20% of Earth's surface; separates the Old World (Europe/Africa) from the New World (Americas). • **S-shape** — the Atlantic is roughly S-shaped, reflecting how the American and African/European continents fit together like puzzle pieces (evidence of plate tectonics). • 💡 Wrong-option analysis: Indian Ocean: third-largest, not the second; Southern Ocean: fifth ocean (recognized 2021), smallest; Arctic Ocean: smallest of the five, not second-largest.

Correct Answer: B. Three

• **Three continents** = the Equator (0° latitude) passes through South America, Africa, and Asia (specifically the Indonesian archipelago). • **Equatorial countries** — in South America: Ecuador, Colombia, Brazil; in Africa: Gabon, Congo, Kenya, Uganda; in Asia: Indonesia; these regions experience equatorial (tropical) climate year-round. • 💡 Wrong-option analysis: Four: incorrect; only three continents are crossed; Five: incorrect; Two: incorrect — three, not two continents are on the Equator.

Correct Answer: D. North America

• **North America** = the only continent located entirely in the Northern Hemisphere; also entirely in the Western Hemisphere. • **Three ocean borders** — North America is bounded by the Arctic, Atlantic, and Pacific Oceans; it contains Canada, the USA, Mexico, and Central American countries. • 💡 Wrong-option analysis: South America: extends into the Southern Hemisphere (majority lies south of Equator); Australia: entirely in the Southern Hemisphere; Africa: lies in both Northern and Southern hemispheres.

Correct Answer: B. Arctic Ocean

• **Arctic Ocean** = the smallest and shallowest of the five major oceans, centered on the North Pole; almost entirely surrounded by Eurasia and North America. • **Ice-covered** — the Arctic is covered by sea ice (which shrinks in summer); it has very low salinity due to limited evaporation and freshwater inflow from rivers. • 💡 Wrong-option analysis: Atlantic Ocean: second-largest, surrounds no pole; Southern Ocean: surrounds the South Pole (Antarctica), not the North Pole; Indian Ocean: third-largest, in tropical-subtropical regions, not around the North Pole.

Correct Answer: C. Asia

• **Asia** = continent where the Tibetan Plateau (Roof of the World) is located; it is the world's highest and largest plateau, averaging ~4,500 m elevation. • **River source** — the Tibetan Plateau is the source of major rivers: Indus, Ganges, Brahmaputra, Yangtze, Mekong, and Huang He; it is also called the Third Pole for its glaciers. • 💡 Wrong-option analysis: Africa: has the Ethiopian Plateau and East African Plateau, but not the Tibetan; Europe: has the Alps and Pyrenees but no high-altitude plateau; South America: has the Altiplano (Andes) — high but not as high as the Tibetan Plateau.

Correct Answer: A. Atlantic Ocean

• **Atlantic Ocean** = has the world's longest mid-ocean ridge — the Mid-Atlantic Ridge, part of the global mid-ocean ridge system stretching over 16,000 km. • **Divergent boundary** — the Mid-Atlantic Ridge runs from the Arctic to near Antarctica through the Atlantic; it is where the North/South American plates diverge from the Eurasian/African plates, forming new crust. • 💡 Wrong-option analysis: Indian Ocean: has the Southwest Indian Ocean Ridge and Central Indian Ridge, parts of the global ridge system but not the longest; Southern Ocean: shares parts of the mid-ocean ridge but the dominant named ridge is in the Atlantic; Pacific Ocean: has the East Pacific Rise (spreading faster) but it is shorter than the Mid-Atlantic Ridge.