Which condition in a nebula would prevent nuclear fusion the presence of nitrogen and carbon the unification of gaseous elements

What are some things that limit population growth?

Which situation is an example of not doing work? lifting a couch throwing a baseball running up stairs carrying a box

Which is a function performed by stem cells in the skin a. replacing lost skin cells b. making cells for the intestines c. growing new organs d. differentiating into brain cells plz apex