the self is in a sense the formidable enemy of a person.
在某种意义上,自我才是自我的最大敌人。
natural disasters are a formidable enemy of the mankind which threaten the lives and subsistence of people in the world and restrict the sustainable development of society.
灾害,威胁着世人的生命和生活,制约着社会的可持续发展,是人类的大敌。
perhaps the builders had heard of a new, formidable enemy that they had not.