Why can't you test two variables in the same trial?

Name three things the framers of the constitution did to keep the federal government or any part of it from becoming too powerful.

Wich characteristics make the long ballot ineffective

Identify the example of when situation and time are key to assessing risk of harm in a research study: a study on the efficacy of a behavioral intervention for smoking cessation involves both adults and teenagersasking women if they have had an abortionresearch on the prevalence of hiv-infected individuals in communitiesa survey about sexually transmitted diseases