Select the correct answer. What was the main economic activity of tribal people who first lived in the Nile River Valley? A. farming B. hunting animals C. domestication of animals D. trade

Plz ! for many generations farmers in north america have been choosing to cross corn plants with large ears of corn each year this results in the new generation of plants also growing large ears of corn. what is the technique called? a. selective breeding. b. natural selection. c. mitosis. d. asexual budding.

When you run, you begin to breathe heavier and faster. your heart beats more quickly, bringing more oxygen to your cells. which organ systems are working together here?

Which condition causes storms to occur