In the control group, how did the number of grass blades change over the three week period?
In the experimental group, how did the number of grass
blades change over the three week period?
Was there a measureable difference in the number of
grass blades between the control group and the
experimental group at the end of three weeks?

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