In order to get around the need for senate approval of treaties, many contemporary presidents have made use of in foreign affairs.

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.        

c

explanation: because you need to reduce the pollution on land,the exhaust fumes will stop,and stop it in water,the oil that is in the oceanharms the fish   sorry if you   have been waiting long