Why are some of the geological time periods not represented in the strata forming the grand canyon? a.)the age of some of the grand canyon's layers is unknown. b.) unconformities resulted in the erosion of some representative layers. c.) during certain times of earth's past, sedimentary layers were not forming. d.)most of the grand canyon's layers are made of igneous and metamorphic rocks.

Paraguay is one of the only two countries in the americas that don't have a coastal border. the country is slightly smaller than california. it was under a military dictatorship for 35 years, ending in 1989; today it is a constitutional republic. most of the population is roman catholic, and over 60% of the people live in cities. its environment is threatened by deforestation and water pollution. which of the following facts from the paragraph above best describes an element of paraguay's culture? (apex)