Test analysis: bottled water is isolated from the outside world and bacteria can't get in. Once opened, use it up as soon as possible, otherwise it is easy to breed bacteria. Even slightly deteriorated food contains the end products (toxins) of microbial metabolism, which cannot be eaten after being cooked at high temperature. B is correct; The transmission routes of AIDS are mainly blood transmission, sexual transmission and mother-to-child transmission, and normal contact will not cause infection. C is wrong; Protein is the basic substance that constitutes human cells. Young students in the period of physical growth and development should eat more foods containing protein, such as fish, meat, milk and eggs. D is correct. So choose: C.