Moscow, April 25: The questions came fast: What’s the cheapest car in America? Are there many service stations? How do you sell a car ? How do classified ads work ? Can Negros ride on buses ? Why is your medical care so expensive ? Isn’t Angela Davis being persecuted because she is black and a communist ? What do you think of the war on Vietnam ? A young American sporting sideburns a handlebar moustache and brightly striped shirt leaned back against a mustard coloured Pinto subcompact car and fielded queries from some of the 17,000 Soviet citizens who flowed daily through the American exhibition on research and development at Moscow’s Sokolniki Park. Often, the listeners’ faces showed surprise at the answers. The size and intensity of the crowds comes in the face of obstacles that have made some American officials believe that the travelling exhibition is the part of the American-Soviet cultural exchanges that Soviet authorities dislike the most apparently because it gives ordinary citizens a chance to check out the information they receive about America in the Soviet press.