Fact 1: Viruses cannot reproduce by themselves. Fact 2: Influenza is a disease caused by viruses. Given the two facts above, which of these diseases cannot reproduce by itself?
pick from the following.
(1). fever.
(2). Leptospirosis.
(3). animals.
(4). influenza.
(5). bacteria.
(6). heat or cold.
(7). dangerous.
(8). anemia.
(4).