Cross-contamination is
(1) crossing two microorganisms during reproduction to produce a heartier strain, (2) getting sick from two different microorganisms at the same time, (3) not keeping hot foods hot and cold foods cold, (4) transferring microorganisms from an original food source to another food source by unclean hands, knives, cutting boards, etc., (5) 3 and 4
Question 2
Compounds that can act as an acid or a base, depending on conditions, are said to be
(1) ambidextrous, (2) conjugated, (3) amphoteric, (4) esoteric, (5) none of these.