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.

c.more precipitation,but only when emission levels.

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.