. Which of the following kinds of cells do not have a short life span? A)skin cells
B)fetal cells
C)kidney cells
D)intestinal cells

The theories on the expansion of galaxies maybe re-examined to strengthen science should not be tested to strengthen science will weaken scientific knowledge if they change will become laws if they don't change

In this experiment, the was intentionally manipulated. it is the independent variable. the dependent variables that were measured were the

Which of the following is a reason why early living organisms on earth could not have survived on the surface? 1. the lack of an ozone layer 2. the lack of oxygen in the atmosphere 3. the fact that these organisms were single-celled