World Economy and Economic Sectors
Sectors and structure
The economy is divided into primary (extraction), secondary (manufacturing), tertiary (services) and quaternary (knowledge and research) sectors. As economies develop, employment shifts from primary to secondary to tertiary; this is the sectoral shift. The Clark-Fisher idea links income growth to service expansion. Know the difference between subsistence and commercial agriculture, extensive and intensive farming, and heavy versus light industry.
Location and trade
Industrial location depends on raw materials, energy, transport, labour, market and capital. Globalisation links production across borders through trade, investment and multinational firms; comparative advantage explains why countries specialise. Trade balances compare exports and imports; a surplus means exports exceed imports. Know major economic blocs and the meaning of tariffs, quotas and subsidies.
Traps
Don't call tourism or banking primary; don't confuse extensive (large area, low input per hectare) with intensive (high input per hectare); and remember that a trade deficit is not the same as a budget deficit.
Worked example
A country exports goods worth 300 billion and imports 340 billion. The trade balance is 300 − 340 = −40 billion, a deficit of 40 billion. If tourism earnings of 50 billion are added to exports of services, the picture can reverse, so read the question carefully.
Regional Geography of the World
Regions and characteristics
Regional geography groups countries by physical and human traits. Know the continents and major regions: Europe, Asia, Africa, North and South America, Oceania and Antarctica. For each, recall climate zones, relief, key rivers, population patterns and economic character. Examples: Africa's rift valleys and the Nile; Asia's monsoons and Himalaya; Europe's mild westerly climate and dense urban network; the Americas' mountain chains and river basins.
Comparisons that examiners like
Be ready to compare developed and developing regions, coastal and landlocked states, and tropical and temperate economies. Know major straits, canals and seas as transport nodes, and the significance of the Mediterranean, the Black Sea and the Danube corridor for Bulgaria and Europe.
Traps
Avoid overgeneralising a continent (Africa is not uniformly hot or dry); don't confuse the Equator with the tropics; and be careful with hemisphere facts, such as that most of South America lies in the Southern Hemisphere.
Rule of thumb
Anchor each region with a triad: one physical feature, one climatic trait and one human or economic trait. For example, the Mediterranean: mountain-fringed coasts, dry summers and mild wet winters, and tourism plus intensive irrigated farming.
Geography of Bulgaria
Relief and structure
Bulgaria lies in southeastern Europe, on the Balkan Peninsula, bordered by Romania (Danube), Serbia, North Macedonia, Greece, Türkiye and the Black Sea. Its relief is varied: the Balkan Mountains (Stara Planina) cross the centre, the Rila-Rhodope massif dominates the southwest, and the Danubian Plain lies in the north. Musala in Rila is the highest peak (about 2,925 m).
Climate, water and nature
Climate is temperate continental in the north and transitional Mediterranean in the south, with Black Sea influence along the coast. The Danube forms most of the northern border; other rivers include the Maritsa, Iskar, Yantra and Tundzha. Bulgaria has mineral springs, Black Sea resorts and diverse protected areas.
Population and economy
Sofia is the capital and largest city; other major cities include Plovdiv, Varna, Burgas and Ruse. The population has been declining and ageing, with urban concentration. The economy has strong services, tourism, agriculture (rose oil, grains, vegetables) and industry, and Bulgaria is a member of the European Union.
Traps
Don't place the Balkan Mountains in the southwest (that is Rila-Rhodope); don't claim Bulgaria borders the Aegean (it does not); and don't confuse the Danube border with a southern border.
Rule of thumb
Remember Bulgaria as three belts: northern plain, central mountains, southern massif, with the Black Sea to the east and the Danube to the north.