What was one of the challenges doctor salk faced in his attempt to create a polio vaccine ?

Read this excerpt from lorraine hansberry's a raisin in the sun: based on the character description, what can the reader infer about travis? a. he is organized and has an established morning routine. b. he has inherited his good looks from his mother, not his father. c. he doesn't like having to share a bathroom with other families. d. he is a little boy of about 10 or 11.

Analyze lowell’s use of symbolism in the poem “for the union dead.” explain how lowell’s use of symbolism to develop one or more themes in the text.

Ihave only a christmas cards left to write. a. few b. fewer c. less d. little