What is the name of the super continent formed 335 million years ago?

Which of the following substances is not involved in the chemical reaction that pro- duces smog? a. sunlight b. particulate matter c. automotive exhaust d. ozone

The body is protected against harmful flu viruses by

Which of the following is true of microbes? a. ninety-nine percent of all microbes are pathogenic.b. gene expression in bacteria is very similar to gene expression in humans, which facilitates the use of bacteria in recombinant biotechnology and gene therapy.c. all bacterial enzymes are harmful to humans and the environment.d. microbes create pollutants and toxins that harm the environment.