What is the main criterion used by the World Bank in classifying different countries? What are the limitations of this criterion, if any?​

Dr. redbull conducts a study to determine whether her new energy drink children perform better on spelling tests. she randomly assigns children to one of two groups: group 1 receives her energy drink and group 2 receives water. she then gives both groups a spelling test and compares the results. which of the following is true about this study? a. group 1 is the dependent variable and group 2 is the independent variable. b. this is a correlational study. c. group 2 is the experimental group. d. the independent variable is the type of drink the children receive.

Which sentences describes a cycle of dependency? a. aid harms the local economy creating the need for more aid.b. aid improves infrastructure and creates more wealth and more good infrastructure.c. aid programs become more reliable over time so people can depend on them.d. no answer is correct

In exchange for land, a knight agrees to be a sort of sub-vassal to a vassal. this agreement was known as: investiture homage tyranny subinfeudation