Doctors have been looking for a cure for which disease since 1981? . polio. cancer. aids. tuberculosis

What makes this speech a primary source? o a. the words are spoken by the president himself. o b. it uses narrative to keep the reader's attention. o c. it was written over 70 years in the past. o d. it contains a strong historical argument.

Ahistorian is writing a book about british prime minister winston churchill. she claims that churchill was one of the earliest british leaders to realize that nazi germany was a serious threat to british security what is the best way to determine whether the historian's interpretation is valid? o a. review primary sources to see if churchill ever recorded his opinions of nazi germany. o b. find out whether the historian has written any other books about british leaders. c. analyze secondary sources summarizing the effects of nazi germany on great britain. o d. cite the historian's book in another study about important 20th- century world leaders.

Which best describes the impact of the crusades on european exploration?