There are instances
that when we are exposed to virus or bacteria, the antigen A in our body try to
fight but still we get sick, take some medication and we are then healed. Then,
another exposure to a new virus or bacteria, the antigen B reacts weakly for
our immune system do not recognized the foreign pathogen that invade the body
resulting to slight sore throat after visiting your sister at school.
Carbon dioxide, and Sulfur dioxide, because you have to know what gas are very dangerous and which ones arent........
Statements 2, 3, 5. the second statement is kinda iffy, but it should be logical
