Scientists conduct a study in which 100 adults with chronic diarrhea are divided into 2 groups of 50 people. one group is given a supply of yogurt that contains a certain kind of bacteria and the other group is given yogurt that is bacteria free. the study's participants and researchers do not know which group of subjects has the bacteria in the yogurt and which group does not. the scientists instruct the participants to eat the entire 8 ounces of yogurt once a day for a month and record the their bowel habits. this is an example of a(n)

Agroup of 50 adult male humans were in a clinical study to determine how much niacin is toxic. during the first two weeks of the study, members of the group consumed only a formula diet that was nutritionally complete, except it contained 24 mg niacin, which is 1.5 times the rda for niacin (males). at that point in the study, all members reported feeling fine. during the next week, they were given a formula that contained 48 mg niacin. within a few days of consuming this formula, 90% of the participants reported feeling ill, and they complained of having upset stomachs and reddened facial skin. at that point, researchers gave the subjects a formula that contain 16 mg niacin. after a week of consuming the new formula, all participants reported feeling well again. based on this information, the researchers concluded that the amdr for niacin is between 16 and 24 mg/day. ul for niacin was between 24 and 48 mg/day. human requirement for niacin is 16 mg/day. eer for niacin was 16 mg/day.

When is it most common for humans begin to develop a sense of self worth? a. adolescence b. early childhood c. infancy d. late childhood

Social sciences are the observable facts or events that involve human society. select the best answer from the choices provided t f