2009 National Question 1 Single-choice Differentiating 2009_旧全国 II 卷 (2009·理) 1.(5分)$\frac{10 i}{2-i}=$ A. $-2+4 \mathrm{i}$B. $-2-4 \mathrm{i}$C. $2+4 \mathrm{i}$D. 2-4i Answer keyA ☆ SaveCan't do it, show the explanation查看原卷 →