Cuáles mecanismos y recursos se han desarrollado en el presente Siglo XXI que vienen impactando el conocimiento de la realidad?

step-by-step explanation:

descending order means to order the polynomials from the term with the largest exponent to the term with the smallest exponent.  

therefore, the correct answer is d.  

ca = ec

cpctc makes it so that corresponding parts of the triangle you proved to be equal are equal, the other options aren't part of the part of the triangles you proved to be equal.