Vertebrates developed about 550 million years ago. The oldest vertebrate fossils are those of FISH with no jaws. These e<span>arly jawless fish did not have paired fins and their bodies were covered with heavy, bony scaled, but their skeletons were made of cartilage. For the next 50 million years, they were the only vertebrates.</span>
Drilling is the result of fertilizer not working.
Answer:the correct option is B
(Streptococcus).
Explanation:
Acute necrotizing ulcerative gingivitis (ANUG) occurs due to poor oral hygiene which encourages plaque to form on teeth, causing inflammation of the surrounding gum tissues. The microorganisms that are known to inhabit the damaged tissues are oral spirochaete which includes Borrelia,Fusobacteria, Bacteroidese and Peptostreptococcus. Streptococcus is not an oral spirochaete therefore is excluded. I hope this helps.