What causes ripple marks? How can they be used to indicate the position of a layer of sedimentary rock?

Ripple marks are sedimentary structures and indicate agitation by water (current or waves) or wind. Ripple marks are ridges of sediment that form in response to wind blowing along a layer of sediment. ... The symmetry of water-current ripple marks indicate whether they were formed by gentle waves or faster water currents.

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.