双重性的英文：
dualism

The damage may be twofold: infected plants may produce less grain, and the quality of the grain itself may be lessened.
病害的破坏是双重性的，一方面感病植株麦粒减少，另一方面麦粒本身的质量也降低。

The essence of Manichaeism was the principle of absolute Dualism: the primal conflict between God, represented by light and spirit, and Satan, represented by darkness and the material world.
摩尼教的本质是绝对的二元论法则：神和撒旦最初的斗争，表现为光明与精神世界和黑暗与物质世界。