Derailleur gears by 13 drive-train. Most road bicycles have two chainrings, and touring bicycles commonly have three. The rear derailleur serves double duty: moving the chain between rear sprockets and taking up chain slack caused by moving to a smaller sprocket at the rear or a smaller chainring by the front derailleur. In order to accomplish this second task, it is positioned in the path of the bottom, slack portion of chain. Sometimes the rear-derailleurs are re-purposed as chain tensioners for single-speed bicycles that cannot adjust chain tension by a different method. Although variations exist, as noted below, most rear derailleurs have
Word sort to help students who do not have extensive reading vocabularies focus on isolated sounds (Initial, final, or medial) within a spoken word. These sorts are often a child’s first introduction to word study and are most commonly used with students whose developmental skills are at the emergent, letter name-alphabetic, or early within word Spelling Stages. Word sort activities involve students comparing, contrasting, and classifying words - considering words from a variety of perspectives. Bear et al. emphasized the importance of comparing those words that do fit into a particular category with those that don't. This type of engagement with words