Answer:
B
Explanation:
Gradually decrease the amount of time spent performing rituals.
If I know the delta u are talking about , it is a mathematical meaning . Both meaning begin with a D just like the Greek letter , which should help u remember
Human's have destroyed some if not most of the chimpanzee habitat, so if we want to keep seeing chimpanzees in the future, then yes, it is our duty to preserve what is left of their habitat.
Answer:
it was only 90 percent effective
Explanation:
In 1954 a massive controlled field trial was launched, sponsored by the National Foundation for Infantile Paralysis. Almost two million U.S. children between the ages of six and nine participated. In some areas of the country half of these “Polio Pioneers” received the vaccine, while half received a placebo. In other areas of the country children who did not receive any vaccine were carefully observed. On April 12, 1955, Thomas Francis, Salk’s mentor and the director of the trial, reported that the vaccine was safe, potent, and 90% effective in protecting against paralytic poliomyelitis.
Covalent bonds share electrons between two atoms.
