Im behind please help me fast! :\

Describe the technology advancements that lead to explorers being able to sail great distances. [[ps: doesn't explain where. i am only speculating it's in europe.

Which action bestillustrates the process of making an interpretation? a. a historian reads a secondary source about the cold war to find out the dates and locations of important historical occurrences. important historical occurrences, b. a historian publishes a popular article about racism in 20th- century south africa but does not cite any sources. c. a historian writes a textbook designed to teach college students about the duties of a professional historian. d. a historian reads speeches by english and french leaders during world war il to differentiate between their content and tone.

Why are slanted roofs found on many buildings within russia and finland? a. to prevent ice slides. b. to prevent the build-up of water during heavy rains. c. to prevent heat from escaping during the clod winter months. d. to prevent snow build-up.