A、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-ascii-font-family: ">线段的端点</span>
B、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-ascii-font-family: ">选中线段的中点</span>
C、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 10.5pt; mso-ascii-font-family: ">选中圆心</span>
D、<span style="FONT-SIZE: 10.5pt;"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">选中上述三特殊点中离当前光标最近的一个</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt"></span><p></p><p></p></span>
D、<span style="FONT-SIZE: 10.5pt;"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">选中上述三特殊点中离当前光标最近的一个</span><span lang="EN-US" style="mso-bidi-font-size: 10.5pt"></span><p></p><p></p></span>