Hi please help me with these two questions

Which of the following is a possible reason for sleep? a) growth b)digestive c)speed d)intelligence

Apopulation has 1000 individuals. over a period of 1 year, 500 newindividuals are born. which equation shows how to calculate the birthrate ofthis population? a. 500 - 1000 = 0.5b. 1000 x 0.5 = 500c. 1000 - 500 = 2d. 1000 + 500 = 1500

Which of the following is a limitation of a clinical trial? a.)amount of random assignments b.)hospital cost c.)number of test tubes d.)amount of peer review