Abstract: A pen instrument is provided with a controllable whistle. The whistle includes a tubular body; a sleeve connected at a rear end to a first open end of the tubular body and at a front end to a rear end of the pen instrument to connect the whistle to the pen instrument; a whistle-producing reed structure fixedly provided in an inner space of the tubular body and including a reed; and a cut-off device provided at a predetermined position on the tubular body and operable by a user to allow or cut off flowing of air through the inner space of the tubular body. A balloon is connected to a second open end of the tubular body and inflated when the cut-off device is in a position allowing air to flow through the tubular body into the balloon.

Abstract: A water supply system for supplying water by condensing air humidity is disclosed. The water supply system is provided with a housing adapted to be mounted on a building. An air humidity condensing system is mounted in the housing to condense air humidity to water. A water collector is arranged below the air humidity condensing system for collecting the water collected by the air humidity condensing system. A water-storage tank is used to storage the water and then supply the water via distributing ducts to the building. A solar collector panel is further supported over the housing to supply electric energy by converting solar energy.

Abstract: A decorative unit structure composed of a first decorative unit and a second decorative unit separably combined with each other is diclosded. The center of the bottom of the first decorative unit is formed with a central extension post. Two sides of the bottom of the second decorative unit are formed with two extension posts spaced from each other by a certain distance. A bight bottom edge is defined between the two extension posts. When combining the first decorative unit with the second decorative unit, the central extension post of the first decorative unit is extended into the space between the two extension posts of the second decorative unit to form an inter-engaged structure having three supporting points which enable the first and second decorative units to be stably rested on a plane face. After combined, the first and second decorative units define therebetween a receiving room for a decorative article to rest therein.

Abstract: A ball-delivering-and-catching device the structure of which allows a ball or the like to roll back and forth thereon and then fly into the air moving along a parabolic path before falling down into or outside a catching hoop if a user grips a handle of the device and adequately sways the device forward and backward. Catching hoops with different shapes showing desired ball games may be used along with matching ball of achieve more fun. Furthermore, different pictures or cards showing different ball games may be selectively inserted into grooves formed on a backboard of the device to enhance the excitment.

Abstract: A spark-producing mechanism for wheel assembly comprises a plurality of flints, a fixing ring for the mounting of flints which closely fits to the shaft of the wheel, a grindstone which is inserted in the interior of the wheel. By rotating the wheel, the flints rub against the grindstone to produce sparks.

Abstract: An arithmetic counter that includes a U-shaped support structure for a horizontal rod. Consecutively numbered beads are slidably arranged on the rod for adjustment to positions wherein selected numbers of the beads are separated from the remaining beads. One or more marker boards are adopted to be hung from the rod between the separated beads and the remaining beads, such that a small child can count the beads and achieve and better understand "addition" and "subtraction" processes.