American children will surely envy Russian students for the challenging and varied activities offered them through the kruzhki (""circles"") of the Young Pioneers. Photos of a cosmonauts club, an expedition of a group of Young Sevastopolist sailors, and a children's railroad with five miles of track and four stations attest to the extent of well-funded projects, and examples of art work, photography, and crafts are similarly impressive. Sports, about which U.S. children are sure to be curious, are not included; nor is there any reference to the Pioneers' political function (it's stressed throughout that participation is voluntary, though since membership is ""considered an honor,"" few choose not to join). Ms. Morton, the successful translator and editor of A Harvest of Russian Children Literature, 1967, includes firsthand observations made during a 1971 tour of kruzhki in many regions of the Soviet Union -- some circles are dedicated to public service, while another, called ""The Daring!"" gathers for ""criticism of leading authors and other cultural matters."" For children, the author Offers a rare glimpse of the diverse accomplishments of their Soviet counterparts, while adults may find a few ideas worth trying out here (one library circle acted out stories and read reviews for television), and both groups should respond to the tone of alert enthusiasm.