Light is focused onto the of the eye to create an image.
a. pupil
b. retina
c. lens
d. iris

Iron reacts with oxygen to produce iron oxide (rust). this reaction is represented in an equation as 4fe + xo2 → 2fe2o3. identify the value of x that will balance the equation.

Which medullary index indicates a human hair? a. 0.653 b. 0.733 c. 0.516 d. 0.256

During an experiment, readings for blood pressure in a persons body were found to be constant . however , when he measured by a different blood pressure cuff , the readings differed by 15 points for each reading. this difference indicates that the results are