After our country paid off its foreign debt to the Soviet Union, there was an incident involving pig tails and apple sifting. Who can tell me?

The Soviets were tired of eating pork. They didn’t want pork but pig tails. Carloads of pig tails were shipped to the Soviet Union, and it was unknown how many pigs had to be killed to get enough. At this time, the Soviets were more picky about fruits. If there was one rotten apple on a wagon, all sixty tons of apples on the wagon would be returned to you. A large number of apples are piled up in the warehouse of Manzhouli Station. In order to reduce losses, all primary and secondary schools in the city were closed, and all teachers and students had their fingernails trimmed to complete the political task of picking apples. The apple should be held in the palm of the hand and checked in circles to ensure there are no bruises or rotten spots. Then wrap it with white paper, put it into a carton with corrugated partitions, fill it with chaff and seal it, and then nail the wooden box.