Denning is another word to use for hibernation. Bears, like the black bears seen here, den during the winter because A) it is very cold. B) food is hard to find. C) they are tired from hunting all summer. D) the days are short and the nights are long.

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 !