Africa was one of the sites where agriculture began. Archaeological investigations suggest that knowledge of cultivation moved west from the ancient Judaea (southern Palestine) and arrived in the Nile Delta in Egypt about the fifth millennium before Christ. Settled agriculture then traveled down the Nile Valley and moved west across the southern edge of the Sahara to the central and western Sudan. By the first century B.C., settled agriculture existed in West Africa. From there it spread to the equatorial forests. African farmers learned to domesticate plants including millet, sorghum, and yams. Cereal-growing people probably taught forest people to plant regular fields. Gradually, African farmers also learned to clear land by burning. They evolved a sedentary way of life – living in villages, clearing fields, relying on root drops, and fishing.

1. In this passage, people who are sedentary are those who:
A. migrate.
B. domesticate animals.
C. burn forests.
D. live in villages

is it D

2. What is the main idea of this paragraph?
A. Agriculture reached Africa first in Egypt.
B. African farmers domesticated millet, sorghum, and yams.
C. Agriculture reached Africa early and developed slowly.
D. African farmers learned to clear land by burning.

is it D

I agree with your first answer, not not the second. A main idea is for the whole paragraph, not just part of it.

is it B

Both your guesses for the 2nd question are too detailed. They're incorrect.

1. Yes, the correct answer is D. In the context of the passage, sedentary refers to people who live in villages, which is mentioned in the last sentence of the paragraph.

2. No, the main idea of the paragraph is not focused on African farmers learning to clear land by burning. The main idea is that agriculture reached Africa early and developed slowly. The passage provides a chronological account of how the knowledge of cultivation traveled from Judaea to Egypt and then spread westward across Africa, with settled agriculture existing in West Africa by the first century B.C., and gradually spreading to the equatorial forests. The mention of African farmers learning to clear land by burning is just one aspect of the development of agriculture in Africa.