Which of these are natural resources that countries trade? Rocks and minerals
Technical support
Phone repairs
Tourist services

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

answer; does not include a reference to the audience;

answer; the georgia militia men mortally wounded their commander;