What physical geographic feature slowed the spread of Islam into Southern Africa?

The Sahara  

Explanation:

It formed the southern boundary of Islamic lands in Africa, which made the empire stop at that physical barrier because traders and armies would have found it difficult to survive in the desert.

Hope this helped! :D

answer: what was the us involvement in ww1? although the u.s. tried to remain neutral when ww1 broke out, it finally joined on april 6, 1917 after declaring war on germany. the reason for america to become involved in ww1 was germany's unrestricted submarine warfare, which had already sunk several american merchant ships.

explanation:

hello! : )

i think a judge or jury, as they preside over the court and is the central figure in a trial.

hope this and i hope i answered in time!

good luck!

~ destiny ^_^