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.  is the answer b?

The answer is d. when it begins to fall back to the child's hand

Schools are being forced to embrace computers. unlike their "digital immigrant" teachers, these students are "digital natives", born into a world where technology is an integral part of everyday life. almost every student has access to a multitude of computers, laptops and tablet devices. it would be crazy to assume an assignment would  notbe written on computer in this day and age.many schools now have a 1-to-1 computer policy, and many districts and states in the united states have mandated computers or ipads across the state for every student,  including los angeles, the second largest school district in the country.but the thing is, when they tried it in la, it wasn't the success they hoped for. that's because the tablets weren't used as much as they expected. rather, it appeared there was a gap between the digital native's love of technology and their use of it in the classroom.this conflicted relationship with computers is also underscored by much of the literature on education. it is also highlighted in professional development and conferences such as  edutech.