现有3个同时到达的作业J1、J2、J3，它们的执行时间分别是T1、T2、T3，且T1。系统按单道方式运行且采用短作业优先算法，则平均周转时间是（ ）

A、<span lang="EN-US">T1</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＋</span><span lang="EN-US">T2</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＋</span><span lang="EN-US">T3<span style="mso-spacerun: yes"></span></span>

B、<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">（</span><span lang="EN-US">T1</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＋</span><span lang="EN-US">T2</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＋</span><span lang="EN-US">T3</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">）</span><span lang="EN-US">/ 3</span>

C、<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">（</span><span lang="EN-US">3T1</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＋</span><span lang="EN-US">2T2</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＋</span><span lang="EN-US">T3</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">）</span><span lang="EN-US">/ 3<span style="mso-spacerun: yes"></span></span>

D、<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">（</span><span lang="EN-US">T1</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＋</span><span lang="EN-US">2T2</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＋</span><span lang="EN-US">3T3</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">）</span><span lang="EN-US">/ 3</span>

A、<span lang="EN-US">T1</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">＋</span><span lang="EN-US">T2</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">＋</span><span lang="EN-US">T3<span style="mso-spacerun: yes"></span></span>

B、<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">（</span><span lang="EN-US">T1</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">＋</span><span lang="EN-US">T2</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">＋</span><span lang="EN-US">T3</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">）</span><span lang="EN-US">/ 3</span>

C、<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">（</span><span lang="EN-US">3T1</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">＋</span><span lang="EN-US">2T2</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">＋</span><span lang="EN-US">T3</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">）</span><span lang="EN-US">/ 3<span style="mso-spacerun: yes"></span></span>

D、<span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">（</span><span lang="EN-US">T1</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">＋</span><span lang="EN-US">2T2</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">＋</span><span lang="EN-US">3T3</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: \'Times New Roman\'; mso-hansi-font-family: \'Times New Roman\'">）</span><span lang="EN-US">/ 3</span>