What did they use to build the hotel?

The Little Morocco is a beautiful building. We used stone and mud to build the hotel. There are skylights – windows in the roof to let light in – so we save electricity. The skylights give us light in the day, so we don’t use electric lights. We don’t use chemicals to clean the rooms because we don’t want to damage the environment.    
    You can walk in the mountains near the hotel and see lots of local wildlife. Enjoy a boat trip on the lake and see the amazing waterfalls, or visit the beautiful caves.
38.    What did they use to build the hotel?
………    
39.    How can the skylights help us to save electricity?
..    
40.    Why don’t they use chemicals to clean the rooms?
..    
41.    What can you see in the mountains?
..