Why do you think some people are more altruistic than others?​

When zhang qin went to explore west, he brought back stories of

Pj conducts an experimental study on the effects of soft music during high stakes science testing. he randomly assigns students at the school. in one condition he does not provide music for testing while in the other group he does provide the music. he administers a pretest at the beginning of the year and a posttest at the end of the year. pj’s design is best described as a: a. static group comparisonb. pretest-posttest control group designc. control-group-time-series designd. nonrandomized control-group pretest-posttest design

Which of the following policies is an example of a command-and-control policy? a. subsidies to education b. maximum levels of pollution that factories may emit c. tradable pollution permits d. none of the above is an example of a command-and-control policy.