20. (A)deliver (B)exert (C)place (D)impose

29. According to the first paragraph, what does the periodic table make visible about natural phenomena？ (A)That they are irreducibly chaotic at the most basic level. (B)That they consist of an infinite plurality of distinct kinds. (C)That they cannot be explained without reference to musical structure. (D)That they can be explained through a finite set of elements and relations.