Is painting a door a physical or chemical change ?

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.

How does human environment effect the biosphere

Other than earth, is also known to have magnetic pole reversal? a: venus b: mars c: earths moon d: the sun