What will be different if the syringes and tube are filled with air instead of water? Explain your answer​

Which of the following statements most accurately describes the requirement for the documentation of minors’ assent to participate in research? parents must approve written documentation.documentation is required unless waived by an irb.to protect minors documentation is always required.federal regulations do not require the documentation of minors’ assent.

Dr. robbins wants to know if there are different opinions regarding the value of public school education between native americans who have at least one relative who attended indian boarding school and native americans who have no family experience with indian boarding school. dr. robbins contacts 35 native american participants in each group. he wants each group to include younger as well as older adults, and a mix of male and female participants. he asks each person to complete a survey about their attitudes toward public education. the design of this study is:

Statement best describes the main reason behind the establishment of government in the early river valley civilization‘s