Why does Sean Brady feel optimistic about the discovery of this new antibiotic?

What is the name of the two satelites on mars

2. which is the last step in the scientific method?

What does polymerase chain reaction (pcr) do? o a. separates dna fragments by size o b. cuts a dna sample into fragments o c. provides an overall picture of a person's chromosomes o d. makes more copies of a sample of dna