Cells undergo differentiation during embryonic development.

If (a, b) is the solution to the system of equations shown above, and a and b are integers, then what is the value of a+b?

What kinds of antigens are found on the rbcs of a person with a+ blood

Which of the following must happen in order for productivity to increase? a. production levels remain unchanged while inputs increase. b. production levels rise while inputs decrease. c. production levels fall while inputs increase.