What is the opportunity cost in this scenario? Gretchen earned $500 from her summer job. She made a list of things that she wants to do with the money she earned. She thought of
spending $100 to buy a guitar amplifier, enrolling in a ballet class for $200, buying new clothes worth $100, and giving her mom a silver necklace
worth $100. When she went to buy the amplifier, she found it cost around $150. She knew that she couldn't change the fee for the dance
classes. So she had to adjust the budget for her clothes or her mom's gift.
In the end, she decided she would buy one pair of jeans instead of the two pairs of jeans she had planned.

Afull irb committee meeting is convened and one agenda item is a new research proposal to evaluate how mothers interact with their learning-disabled child. the inclusion criteria require the children to be a minimum of five years of age. the protocol requires the mother of the child to look at the child without any expression and not to talk to the child for three minutes. the committee determined that the mother's required task may upset the child. the irb approved the study with appropriate language in the parental permission form regarding the possibility that children might become upset. after the start of the study, the principal investigator reports to the irb that, as expected, one of the children became upset. the incident was handled according to the protocol and the child is fine. what should the irb do with regard to this report?

In a citizens elect the president as head of government separately from the legislature. question 1 options: parliamentary democracy communist state presidential democracy autocratic state

Which of the following discoveries would be most likely to cause a scientific paradigm shift? a. the discovery of more rings around uranus b. the discovery of a new pathogenic virus transmitted by mosquitoes c. the discovery that a dormant volcano is showing signs of activity d. the discovery of a new species of salamander in the amazon rainforest e. the discovery that excess heat is radiating from the center of the earth and causing global climate change