what does stubborn mean

Chris has a thrombotic disorder which class of medications would his doctor prescribe to inhibit the thrombosis

Early treatment for mental illness involved because doctors believed that doing this would drain the mental illness out of the person’s body.

Which action occurs in the third stage of cell division? a. the nuclear material of cell is copied exactly. b. the nuclear membrane disappears. c. the cell forms two nuclei d. the nuclear material separates, with half moving to either side of the cell.