The study of planets, the sun, comets, etc

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

Blood stem cells may develop into any kind of human blood cells. what kind of stem cells are blood stem cells? a. multipotent stem cells o b. totipotent stem cells o c. pluripotent stem cells o d. unipotent stem cells

Hemoglobin is a proton that carries oxygen around the body what is hemoglobin made from