|Archaeologists studying Bonito phase (ca. A.D. 900-1140) Native American ceramics from Chaco Canyon, New Mexico, observed that many pots had been altered after firing to revise their decorative designs--usually, intricate geometric patterns painted in black on white slipped surfaces. In some cases, a new design was imposed over an earlier one; less often, the original design was simply covered with white slip. Crown and Wills doubt that the alterations were made to correct design errors. Many Chaco pots with design errors were left unaltered. Furthermore, when errors were corrected, revisions were made prior to firing-either by painting directly over the error or by scraping off designs and applying new slip and paint, which is a less time-consuming method than repainting and refiring flawed pots.|
|The author of the passage mentions Crown and Wills primarily in order to|
|According to the passage, which of the following is true of Bonito phase Chaco pots?|
|Astronomers who study planet formation once believed that comets-because they remain mostly in the distant Oort cloud, where temperatures are close to absolute zero-must be pristine relics of the material that formed the outer planets. The conceptual shift away from seeing comets as pristine relics began in the 1970s, when laboratory simulations revealed there was sufficient ultraviolet radiation reaching comets to darken their surfaces and there were sufficient cosmic rays to alter chemical bonds or even molecular structure near the surface. Nevertheless, astronomers still believed that when a comet approached the Sun-where they could study it-the Sun`s intense heat would remove the corrupted surface layer, exposing the interior. About the same time, though, scientists realized comets might contain decaying radioactive isotopes that could have warmed cometary interiors to temperatures that caused the interiors to evolve.|
|According to the passage, astronomers recognize which of the following as being liable to cause changes to comets?|
Consider each of the choices separately and select all that apply.
According to the passage, astronomers` belief that comets are pristine relics was
|The author of the passage suggests that applying the term "confessional" to the work of the poets discussed|