Iran has a president, however, government decisions are made by a group of religious leaders and are based on Islamic law. What type of government is in place in Iran?

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food