Assuming two hikers begin at a trail start, which scenarios must be true based on the table? Check all that apply. Melissa and Corey started on different trails. Melissa hiked up the trail for a longer period of time than Corey. Melissa and Corey crossed paths between 60 and 90 minutes. Corey began his descent before Melissa. As Melissa’s time increased from 0 to 60 minutes, her elevation decreased.

Tooth enamel consists mainly of the mineral calcium hydroxyapatite, ca_10(po_4)_6(oh)_2. trace elements in teeth of archaeological specimens provide anthropologist with clues about diet and diseases of ancient people. students at hamline university measured strontium in enamel from extracted wisdom teeth by atomic absorption spectroscopy. solutions with a constant total volume of 10.0 ml contained 0.726 mg of dissolved tooth enamel plus variable concentrations of added sr. added sr find the concentration of sr in the 10 ml sample solution in parts per billion = ng/ml. find the concentration of sr in tooth enamel in parts per million = mu g/g.