Task: Question Generation
Input (English): Background Paragraph: About 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. 
Story: Craig is going on some trips this week. The first trip on Monday is to Giant's Peak. The next trip on Friday is to Sleepy's Caves. He is excited to see all the sites.
Output (English): On which day will Craig have a better chance to see limestone formations?