What was the cost of Hitler opening up a war on two fronts, one in Africa and the other in Russia? pls answer, don't tell me what the two fronts are, just answer the question

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.