Concentrations of lead in the bloodstream are often quoted in units of μg/dl. averaged over an entire region, the mean concentration of lead in the blood was measured to be 1.5 μg/dl. express this concentration in ppb. express your answer to two significant figures.

Which statement describes the appearance of a temperature-vs.-time graph? a horizontal line shows that the temperature increases at a constant rate over time. a vertical line shows that the temperature decreases at a constant rate over time. horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases. horizontal lines where the temperature increases are connected by upward-sloping lines where the temperature is constant for each phase.

Which best describes how johannes kepler developed his laws of planetary motion

What does the xylem do? stores the glucose captures the sunlight absorbs oxygen into the leaf carries water from the roots to the leaves