निम्नलिखित में से किस प्रमुख संकुलन (agglomeration) में हमें विश्व की लगभग दो-तिहाई जनसंख्या का सघन जमाव मिलता है?

In traditional anthropological classification of human races, which racial group was characterized as 'yellow-skinned'?

What is the approximate estimated proportion of ecumene (habitable) and non-ecumene (uninhabitable/sparsely inhabited) areas on the Earth's surface?