Read the passage from "optimism.”

a poet once said i must be happy because i did not see the bare, cold present, but lived in a beautiful dream. i do live in a beautiful dream; but that dream is the actual, the present,—not cold, but warm; not bare, but furnished with a thousand blessings. the very evil which the poet supposed would be a cruel disillusionment is necessary to the fullest knowledge of joy.

keller achieves her purpose of convincing the audience by using a

a. fact.
b. quotation.
c. rebuttal.
d. statistic.

She took up a scalpel and slit the monkey's abdomen, making a slow and gentle cut, keeping the blade well away from her gloved fingers. the spleen was puffed up and tough, leathery, like a globe of smoked salami. she did not see any bloody lesions inside this monkey. she had expected that the monkey's interior would be a lake of blood, but no, this monkey looked all right, it had not bled into itself. if the animal had died of ebola, this was not a clear case. she opened up the intestine. there was no blood inside it. the gut looked okay. then she examined the stomach. there she found a ring of bleeding spots at the junction between the stomach and the small intestine. this could be a sign of ebola, but it was not a clear sign. it could also be a sign of simian fever, not ebola. therefore, she could not confirm the presence of ebola virus in this animal based on a visual inspection of the internal organs during necropsy.