One of the following regions has the world's largest tropical peatland, which holds about three years worth of global carbon emissions from fossil fuels; and the possible destruction of which can exert detrimental effect on the global climate. Which one of the following denotes that region ?

The correct answer is A, 1 only. Only the Aral Sea has shrunk drastically because of human activity.

The Aral Sea, on the border of Kazakhstan and Uzbekistan, was once the world's fourth-largest lake. From the 1960s, Soviet planners diverted its two feeder rivers, the Amu Darya and the Syr Darya, to irrigate cotton fields, and the lake lost most of its area, splitting into smaller bodies and leaving a salty desert, the Aralkum. The Black Sea is a large inland sea joined to the Mediterranean through the Bosporus and has not dried up. Lake Baikal in Siberia, the world's deepest and oldest freshwater lake, faces pollution but has not shrunk away.

B is wrong: neither the Black Sea nor Lake Baikal has dried up.

C is wrong: the Black Sea has not shrunk.

D is wrong: Lake Baikal has not shrunk immensely.

Exam tip: Aral Sea = Amu Darya and Syr Darya diverted for cotton; Baikal = deepest lake in the world.

The correct answer is A, the savanna of Kenya and Tanzania. The Masai are a cattle-keeping people of the East African savanna, moving their herds with the seasonal rains; their life is the standard textbook example of pastoral nomadism in the tropical grasslands. B is wrong because the people of the Congo rainforest named in textbooks are the Pygmies or Bambuti, who live by hunting and gathering. C is wrong because the Kalahari is the home of the Bushmen or San, also hunters and gatherers, who are famous for tracking and for finding water in a dry land. D is wrong because the steppes of Ukraine are a wheat growing belt of commercial farming, not the home of a named pastoral tribe in the exam syllabus. Match each people with its biome.

The correct answer is C, the Urals. The Ural mountains, an old worn range running north to south across Russia, together with the Ural river, the Caspian Sea and the Caucasus, form the conventional boundary between Europe and Asia, which is why the two are often treated as one land mass called Eurasia. A is wrong because the Alps are young fold mountains within Europe, dividing Italy from France, Switzerland and Austria, and holding Mont Blanc. B is wrong because the Pyrenees separate France from Spain and shelter the small state of Andorra. D is wrong because the Apennines run the length of the Italian peninsula. Only the Urals serve as a continental boundary, and they are also rich in iron, coal and other minerals.

The correct answer is B, the Danube, which rises in the Black Forest of Germany and flows through ten countries before forming its delta on the Black Sea in Romania, more than any other river in the world. It also passes more capital cities than any other river, among them Vienna, Bratislava, Budapest and Belgrade. A is wrong because the Rhine, though the busiest inland waterway of Europe, touches far fewer countries on its way from the Alps to the North Sea. C is wrong because the Nile basin is shared by many states but the main river itself runs through a much smaller number on its course to Egypt. D is wrong because the Amazon, the largest river in the world by volume, flows mainly through Brazil after rising in Peru.

The correct answer is C, the Caspian Sea. The Volga, about 3,530 kilometres long, is the longest river of Europe and flows entirely within Russia to end in the Caspian, which is a landlocked salt lake and the largest lake in the world, so the Volga never reaches an ocean. A canal joins it to the Don and so to the Black Sea for navigation. A is wrong because the Don, the Dnieper and the Danube flow into the Black Sea. B is wrong because the rivers of the Baltic drainage include the Vistula, the Oder and the Neva. D is wrong because the Rhine, the Elbe and the Thames belong to the North Sea drainage, with Rotterdam at the Rhine mouth as Europe's largest port. The Volga and the Caspian form one of the most repeated pairs in world geography.