Bradley decides one day to run a marathon without any training. after ten minutes has elapsed and bradley has run half a mile, he begins to get cramps in his thighs. he is also breathing very rapidly. what is causing the cramps on bradley's legs?

Which statement correctly describes other ways in which nebulae and stars are different? a. a star always has a higher density than a nebula. b. stars can form inside a nebula but a nebula can never be produced by any star. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star. reset submit