2015 Beijing Question 1 Single-choice Differentiating 2015_北京卷 (2015·理) 1.(5 分)复数 $i(2-i)=(\quad)$ A. $1+2 i$B. 1-2iC. $-1+2 \mathrm{i}$D. $-1-2 \mathrm{i}$ Answer keyA ☆ SaveCan't do it, show the explanation查看原卷 →