It is not practical to expect that any society can resolve all the social problems it is faced with______.
【正确答案】 B
【答案解析】解析：句意：期待社会能一劳永逸地解决其面临的所有社会问题并不现实。once for all彻底地，一劳永逸地。back and forth反复地，来回地。by nature天生地。in detail详细地。故选B。