What' New : Activity # 1 I have a Riddle: My teacher has a challenge to me. I must fill the three balloons with different materials provided by my teacher. These include three balloons, pebbles and water. The instruction is to fill the first balloon with pebbles; the second balloon with water. For the remaining balloon, there is no material to put into it. What should I put? In addition, how will I put something it? Remember: No picking and getting materials around you​