Is it possible that people who are free riders in one situation provide more than their share of support in another situation ? give an example .

The persians landed in the plains near athens. as their army greatly outnumbered that of the greeks, the greeks hoped to find aid from nearby sparta. a long-distance runner named pheidippides was sent from athens to sparta to request , but the spartans were not able to send more soldiers at the time. regardless, the greeks were still able to win the battle. centuries later, legend developed that a runner had been sent from the battle to athens after the greek victory. after reaching athens, the runner proclaimed, "we are victorious! " and then fell to the ground and died. this legendary story is the inspiration for the modern long-distance runs that are performed today. this passage refers to the events of which battle during the persian wars? a. battle of thermopylae b. battle of salamis c. battle of plataea d. battle of marathon

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 statement about spreading knowledge of diseases and health around the world is correct?