Abstract: A ball quantitative supply system is comprised of an upper plate, a lower plate and a rotary block rotatably retained between the upper and lower plates. The upper plate is provided with a ball receiving aperture for receiving balls fed from a ball feeder, and a ball confirming aperture for confirming a predetermined number of balls, the apertures being provided to extend through different portions of the plate when seen in top plan. The lower plate is provided with a ball discharge aperture extending therethrough. The rotary block is provided with a ball receptacle extending therethrough for receiving a predetermined number of balls. The positions of provision of the ball receiving aperture, ball confirming aperture and ball discharge aperture are displaced from each other at an equal interval of 120.degree. as viewed in top plan.

Abstract: A method for preparing water-absorbent resins (D) by radically polymerizing a water soluble monomer (A), or a water-soluble monomer (A) and a polysaccharide (B) in the presence of a crosslinking agent (C) and water, wherein the polymerization is conducted under the existence of a thiol compound (E). Water-absorbent resins obtained in the method of the present invention provide high absorption while providing safety with very little amount of a water-soluble component.