In the year 2000, Eduardo Alejandro Jusschan, an 11-year-old boy in Argentina, sees himself skateboarding over a roller-coaster of freeways in the sky.

In Peru, another 11-year-old sketches his vision of the future: a sea of featureless faces jammed into every bit of space against a backdrop of featureless buildings.

An exhibit of children's art from around the world opened last night, at the Capital Children's Museum, giving some glimpses of what youngsters dream, think, and even fear when looking at "My Life in the Year 2000."

"Children must eat, but they also must sing . . . children must be protected, but they also must be able to express their joy and hurt," Jean Childs Young told the guests at the reception.

Young, wife of Andrew Young, former U.S. ambassador to the United Nations, is chairman of the U.S. National Commission for the International Year of the Child. Also on hand was Amadou-Mahtar M'Bow, of Senegal, the UNESCO director-general.

At the beginning of the reception, an unexpected guest arrived and held center-stage for five minutes. He was Danny Kaye, who gained impeccable credentials to appear at any UNESCO or UNICEF function through his long association with United Nations children's programs.

The 45 paintings in the exhibit, which will run through Nov. 15, are among finalists selected from 6000,000 entries from children in 89 countries around the world. The competition was sponsored by UNESCO, UNICEF, and the United Nations High Commissioner for Refugees to mark the International Year of the Child.

Asked to peer into their future, some of the children did, of course, foresee a space-fantasy world in 2000 A.D. But there are also sketches like that by a 12-year-old Greek girl who drew a solid wall of slab buildings under a sooty, dark sky as a sad little girl sits before a droopling blossom that well could be Thurber's "The Last Flower."