Why do scientists do at least 3 trials when conducting an expirement?

Astudent visits the beach during a very hot day she steps on the santa and jumps because it is so hot what type of heat transfer is demonstrated by the sand in this example

Assume that a student is given two different models of bacteria, with one model consisting of big bacteria and the other consisting of small bacteria. how can the student demonstate the theory of endosymbiosis using the models

Animals such as pronghorn antelope, bison ans badgers dot to the landscape. where are these animals located?