PLZ HELP ASAP IM TIMED! Which of the following statements is true?

a.) Sound vibrations are changed into electrical impulses by the eardrum.
b.) It is dangerous to listen to sounds over 160 dBs.
c.) High-pitched sounds have low frequencies.
d.) All of the above.

THERE IS A QUESTION LIKE THIS ON BUT ITS VOTED 1.5 STARS PLZ HELP ASAP PLZ ILL GIVE 25 POINTS PLZ

What problem would a person have if the nucleic acid in one of his or her cells were damaged?

16. in a reaction that has reached equilibrium, a. the forward and reverse reactions are occurring at the same rate. b. the reactants and products are in equal concentrations. c. the forward reaction has gone further than the reverse reaction. d. there are equal numbers of atoms on both sides of the equation. e. a, b, and d are correct.

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.