Alfred Wegener proposed the theory of continental drift around 1912. Which of these components of his theory is now known to be FALSE? Select one:

a. Similar plants and animals live on continents separated by oceans.

b. All existing continents were once joined into a supercontinent.

c. The boundaries of many neighboring continents fit together.

d. The Moon’s gravity and Earth’s spin can move the continents.

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.