Many people with human immunodeficiency virus (hiv) wear a mask to cover their noses and mouths. which statement best explains the importance of the mask? a: it prevents hiv patients from catching airborne diseases. b: it prevents the spread of hiv to nearby people. c: it prevents the dna of hiv patients from becoming faulty. d: it prevents hiv patients from becoming contagious.

What were the main components of earth’s earliest atmosphere? oxygen and ammonia hydrogen and helium oxygen and nitrogen hydrogen and nitrogen

Asolution of an enzyme and a substrate was placed in a water bath and the temperature of the reaction was raised gradually. the graph shown was plotted at the end of the experiment. what can be concluded from the graph? a) temperature has no effect on the activity of the enzyme. b) the effect of temperature on the enzyme is unpredictable. c) the enzyme shows increased activity up to a certain temperature. d) the activity of the enzyme is inversely proportional to the temperature.

Areal dna molecule consists of thousands of these pairs of nucleotides. what is the pairing arrangement of the nitrogen bases