Which describes a galaxy and nebula correctly? A. a galaxy is a solar system with a nebula in the center.

B. a galaxy is a cloud of dust that is the birthplace of stars and a nebula is a star.

C. a galaxy is a system of stars, gas, dust and a nebula is the birthplace of stars.

D. a galaxy is smaller than a nebula but they both are the birthplace of a star.

Scientists are conducting a study on the effectiveness of a new drug on memory loss. they are giving some of the test subjects the new drug to find out if it improves their long-term memory. which are possible limitations of this study? check all that apply. a) test subjects may want to participate in additional experiments. b) test subjects may think they should be paid more. c) test subjects may get bored and want to quit early. d) test subjects may have to travel during the experiment. e) test subjects may have full-time jobs. this is multiple choice. you for the !