What are the answers to questions 13-18 regarding ethnic groups, geography, and history of East Africa?

Here are the answers to your questions:

13. The Dinka ethnic group is known to have migrated from Bahr el Ghazal in South Sudan.

    $$\boxed{\text{Dinka}}$$

14. The main occupations for communities in regions like "Awar Lake Kida" in South Sudan typically include pastoralism (raising livestock), fishing, and subsistence agriculture.

    $$\boxed{\text{Pastoralism, fishing, and subsistence agriculture}}$$

15. The Nuer of South Sudan belong to the Nilotic ethnic group classification.

    $$\boxed{\text{Nilotic}}$$

16. Pubungu is historically remembered as a major dispersal point or the cradle for various Nilotic groups (such as the Luo, Alur, and Acholi) during their migrations. It was a significant settlement before their further expansion.

    $$\boxed{\text{Major dispersal point for Nilotic groups}}$$

17. Two countries in the Horn of Africa are Ethiopia and Somalia.

    $$\boxed{\text{Ethiopia, Somalia}}$$

18. The Cushites preferred settling in the grasslands of Africa primarily because these areas provided abundant pasture for their livestock (cattle, sheep, and goats), which was central to their pastoralist way of life. Grasslands also offered suitable conditions for some agriculture and access to water sources.

    $$\boxed{\text{Abundant pasture for livestock}}$$