该方法不需要安全或者等幂.This method does not need to be either safe or idempotent.这个矩阵是等幂的.This matrix is idempotent.利用差分论证了等幂和一般公式的唯一性,它可用插值法构造,也可用待定系数法求得.It can be structured by interpolation or be got by method of undetermined c...
He gripped his brother's arm lest he be trampled by the mob.他紧抓着他兄弟的胳膊，怕他让暴民踩着。They decided to retreat lest they would be between two fires.他们决定撤退,否则就要受两面夹击.Be careful lest you ( should ) fall from the tree.小心,不要从树上...