2025 Beijing Question 3 Single-choice Differentiating 2025_北京卷 (2025) 3.双曲线 $x^{2}-4 y^{2}=4$ 的离心率为 A. $\frac{\sqrt{3}}{2}$B. $\frac{\sqrt{5}}{2}$C. $\frac{5}{4}$D. $\sqrt{5}$ Answer keyB ☆ SaveCan't do it, show the explanation查看原卷 →