Which of the following are true about bacteria? select all that apply. bacteria are all around you. bacteria can or harmful. bacteria are multicellular organisms. bacteria can only be found on the human body.

The first one because there are many types of bacteria that are harmful and helpful For instance some types of bacteria have side effects  likr pneumonia (Streptococcus pneumoniae), meningitis (Haemophilus influenzae), strep throat (Group A Streptococcus), food poisoning (Escherichia coli and Salmonella), and a variety of other infections.

Some good types of bacteria are Lactobacillus Acidophilus. Dairy products like yogurt are prepared by exposing milk to lactobacillus acidophilus bacteria. there are Streptomyces and Rhizobium that are also good for the human body. I hope I have answered your question.