A. 28. Antibiotics are designed to kill certain species of bacteria, but scientists must continually develop new antibiotics to
combat bacterial infections. What is the best explanation for why this is necessary?
Bacteria have evolved through geographic isolation so the old antibiotics are no longer effective.
b. Bacteria have evolved through reproductive isolation so the old antibiotics are no longer effective.
Bacteria have evolved resistance to antibiotics through natural selection so the old antibiotics are no longer
effective.
d. Bacteria cannot evolve, but the scientists are trying to make more money.
c.

s the president shall be commander in chief of the army and navy of the united states, and of the militia of the several states, when called into the actual service of the united states; he may require the opinion, in writing, of the principal officer in each of the executive departments. sooo yeahhh

explanation:

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation:

they both wanted to stop protestantism, they felt a call in life and it was to strengthen the church. charles used inquisition, philip used army's, charles gave control to outsiders, philip centralized all power.

hope this you !

-he wants to reinforce that students and teachers still have their first amendment rights during the school day.