851、 The work of mathematician Roger Penrose in the early 1970s, on the geometry of what are called aperiodic tiles, turned out to describe the architecture of a previously unknown class of crystals. (A) what are called aperiodic tiles, turned out to describe (B) what is called aperiodic tiles, describes (C) aperiodic tiles, describing (D) so-called aperiodic tiles, describe (E) aperiodic tiles, it turned out to describe