asymmetry of the oscillation causes the bed forms to shift laterally at non-negligible rates. I will unofficially term cross stratification of this kind climbing-bed-forms cross stratification. Bed forms are said to climb when there is overall aggradation of the sediment bed while the bed forms are moving; see a later section for details.) 502
Swahili is the most spoken language in Africa, with over 100 million speakers. It is a Bantu language believed to have originated from other languages, mainly Arabic, due to historical interactions between Arabs from the Middle East and East Africans.
Portuguese is spoken as a first or second language by just over 70% of the population. There are approximately 38 African languages in Angola, including Umbundu, Kikongo and Chokwe. Benin. Official Language: French. There are 55 languages in Benin, the most popular of which are Fon and Yoruba (in the south) and Beriba and Dendi (in the north).