1. what is one feature that distinguishes homo sapiens?
(a) complex spoken language
(b) ability to control complex tools
(c) bipedalism

2. why was it difficult for humans to cultivate land prior to the end of the last ice age?
(a) soil was too cold and hard to break up with the stones.
(b) the large population of other humans made settling in one place dangerous.
(c) all the water that was needed for irrigation was frozen.