Guidelines recommend that preschool children engage in of physical activity per day.

The president of american systems announces that all employees will be going on a trip to san francisco. some employees like the idea and some don't. according to the component of attitudes, these evaluations reflect the feelings of the employees.

Which is relatively better: a score of 76 on a psychology test or a score of 22 on an economics test? scores on the psychology test have a mean of 90 and a standard deviation of 13. scores on the economics test have a mean of 52 and a standard deviation of 10.

The controlled use of fire by hominids: (a) limited the expansion of hominids into certain environments, such as dry grasslands. (b) decreased the amount of food energy available in the hominid diet. (c) contributed to geographical expansion and food production techniques in positive ways. (d) has been shown to contribute little to the digestive process of hominids.