The dichotomous key is used as a classifying tool for items in the natural world, (trees, wildflowers, mammals, reptiles, rocks...). At each step of the classification process,<span> the user is given two choices and each choice leads to another question until the item is identified.</span>
<span>A dichotomous key starts with specific information and leads to general information.
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According to Twain man could not have ascended from lower animals (Darwin theory of evolution) because man makes cruel and horrible decisions, rather man descends from Higher animals. He proved his conclusions about man by using specific scientific method, he subjected every postulate itself to the crucial test of actual experiment and have adopted it or rejected it according to the results.