“牢固的”用英语怎么说

情感冲突可以动摇哪怕是最牢固的人际关系的基础。Emotional conflict may shake the foundations of even the strongest relationship.黏土和砂岩都是不牢固的岩石构造。Both clay and sandstone are unstable rock formations.生活在这种全无隐私可言的环境之下，最牢固的婚姻也会破裂。Living in this goldf...