Which statements describe russian surfs?

they lived in single room cabins made of logs or clay
they owned the land on which they worked
they made up more than three-quarters of the population
they were regarded as the property of the noble who's fields they worked

The first statement that should be made is that the spelling is serfs, not surfs

As for what they were, they were essentially slaves who worked land owned by the nobleman which they lived on, and who were forced to turn their crops over to the nobleman.

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain

answer:

it caused mass african migration, african populations to grow, african empires to topple, and racism against slaves to emerge.