Observation of tool-making among chimpanzees was revolutionary primarily because scientists believed a. chimpanzees lacked the dexterity to make tools b. tool use was a defining characteristic of humans c. tool-making was a defining characteristic of humans d. none of the above

The correct answer is:

c. tool-making was a defining characteristic of humans

Explanation:

They believed that the tool making was a characteristic that was possessed by humans.The initial stone toolmaking increased by at least 2.6 million years ago. The Early Stone Age covers the most basic stone toolkits made by early humans. The Early Stone Age in Africa is comparable to what is described the Lower Paleolithic in Europe and Asia.

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

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