2022 Tianjin Question 2 Single-choice Differentiating 2022_天津 Paper 2. “ x 为整数”是“ 2 1x + 为整数”的( ) A. 充分不必要B. 必要不充 ptsC. 充分必要D. 既不允分也不必要 Answer keyA ☆ SaveCan't do it, show the explanation查看原卷 →