generate questions: Roughly 70% of the area in the RSFSR consisted of broad plains, with mountainous tundra regions mainly concentrated in the east. The area is rich in mineral resources, including petroleum, natural gas, and iron ore.
What percentage of the RSFSR was made up of plains? {sep_token} In what part of the RSFSR did tundra mainly exist? {sep_token} Along with petroleum and iron ore, what resource was abundant in the RSFSR?