Abstract: An interactive learning system has an interactive control unit that displays competition or quiz questions in multiple-choice or other format. Students using the system enter answer choices on a wireless keypad. A base station connected to the interactive control unit receives answer choices from and communicates with the wireless keypads. The interactive control unit keeps track of the scores for all users, and scores of different groups of users (i.e., classes).A receiver connected to the interactive control unit receives content for competitions by satellite broadcast. The competitions are then stored for later use. The system can conduct competitions from those that have been stored or broadcast, or from those that can be created by individual teachers. Previously broadcast and stored competitions can be played simultaneously by a plurality of remote locations, in a "live competition" setting.

Abstract: The present invention relates to a method for enhancing the water-retention capacity of soils and providing plant nutrients to same over an extended period of time. This method comprises the admixing of soils with from 2 to 30% by weight of a chryso-zeolite of type A/and or X which comprises a magnesium leached asbestos matrix having an SiO.sub.2 content of 37 to 60% wt %, an MgO content of 0.1 to 15% by weight, an Fe.sub.2 O.sub.3 content of 0.1 to 2.5% by weight and containing from 10 to 25% by weight of Al.sub.2 O.sub.3 and from 25 to 35% by weight of Na.sub.2 O, and/or K.sub.2 O, and/or CaO, and/or (NH.sub.4).sub.2 O.