When a chain saw is placed on the chain saw mounted and moved towards the trunk of the tree along the guide bars, the tree is cut to a position determined by {HEAD ~ the stop mechanism} on {TAIL ~ the guide bars} 
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When a chain saw is placed on the chain saw mounted and moved towards the trunk of the tree along the guide bars , the tree is cut to a position determined by { HEAD ~ the stop mechanism } on { TAIL ~ the guide bars }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL