What antibiotic is recommended for use against gram negative bacteria?

Ecosystems involve living organisms interacting with non-living things in a productive way; how is photosynthesis an example of this? answer, i will give brainiest to first person to get it right.

The phylogenetic tree illustrates the relationship between humans and our closest living relatives. the tree was based on biochemical comparisons, including dna and amino acid sequences. according to the biomolecular data, we could infer that a) the four organisms do not have a common ancestor. b) humans are more closely related to chimps than any other apes. c) chimps are more closely related to gorillas than they are to humans. eliminate d) there is no evidence if any relationship between the four branches on the tree.

Which is an important function of normal flora? a. aid with bone marrow production. b. crowd out pathogenic bacteria. c. destroy digestive track pathogens. d. manufacture iron in the bloodstream.