A person infected with the human immunodeficiency virus (HIV) may not have any symptoms for a period of time. During this period the virus affects the body by doing which of the following? A. The virus uses nutrients meant for immune cells to fuel its own cellular respiration.

B. The virus produces toxins that weaken immune cells and prevent them from reproducing.

C. The virus changes the identity of the nucleotides of immune cells to prevent the immune system from functioning normally.

D. The virus damages immune cells while using their machinery to produce copies of itself.

Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a.one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b.one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c.one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.