The state of Yugoslavia started to break up in 1991 and ceased to exist about a year later. So to fly from Yugoslavia to Austria would require travelling across time rather than a country.
You can fly from parts of what was formerly Yugoslavia to Austria without crossing any other country.
parallel
parellel lines
A polygon.
Draw a straight line from opposite corners. Where the lines cross is the centre.
Cross country originated from the Crick Run held every year since 1837 at Rugby School in Englands. In the early 19th century
Cross-country: Norway Downhill: Austria
First of all, you would have to travel through time, not just cross national boundaries, because Yugoslavia has not existed for over 20 years!Next, I am not sure what a "strait" line is. There are no straits in the region. On the surface of a sphere (or spheroid) such as the earth, the shortest distance between two points is a arc of the great circle, not a straight line drawn on a map which is a 2-d projection of a 3-d surface.A great arc flight would take you over Hungary.
INDIA
Animals native to Yugoslavia include elk, cross foxes, ducks and geese. The lynx cat is also native to the area.
Straight lines that never cross are called parallel lines.
Cyclo- cross, cross-country mountainbiking, horse cross-country, cross-country rally, motorcross, supercross, cross-country running, cross-country skiing, boardercross, golfcross, lacrosse, and polocrosse.
Austria, Switzerland, France, Italy and Sweden.
cross country
Cross country running started in England
parallel
Cross-Country Crime was created in 1995.
Cross Country USA was created in 1985.