[单选]

As an experienced network engineer, you are asked to troubleshoot a CIS network outage. During the troubleshooting process, you notice that one of your colleagues connects additional devices to the network with the use of his own switch. With the purpose of improving speed, the switch is attached to both network ports in an office, which leads to bridge loop.
Enabling which of the following feature will be able to prevent this problem from happening again?（）

纺制涤/粘65/35混纺纱，在FA002型抓棉机上混用，抓棉机每次上料2000kg，实测涤纶的回潮率为0.4%，粘胶纤维的回潮率为13%，问在抓棉机上各上多少包？（涤包湿重100kg，粘纤包湿重100kg） 下列说法错误的是（） 期货交易和期权交易都可以根据客户需求量体定做。 期货和期权都是金融衍生工具。 期货交易和期权交易双方的权利义务不同。 期货交易和期权交易双方承担的风险不同。 安全生产检查常采用现场检查的方式进行，通过检查可及时发现隐患并采取措施予以消除。现场安全检查方法中，可直接、定量地获取准确信息的方法是（）。 现场观察。 员工访谈。 仪器检查。 在Excel中，若A2单元格中输入数值10，B2单元格中输入了公式“=IF（A2＞20，“A”，IF（A2＞8，“B”，“C”））”，那么B2显示的是（） T。 C。 B。 A。 单调感一般具有下列哪个特点（）。 作业呆板的保持节奏和细节。 虽然能坚持作业，但工作质量降低。 作业时能耗不大，也不易疲劳。 作业能力动态曲线发生特殊变化。

As an experienced network engineer, you are asked to troubleshoot a CIS network outage. During the troubleshooting process, you notice that one of your colleagues connects additional devices to the network with the use of his own switch. With the purpose of improving speed, the switch is attached to both network ports in an office, which leads to bridge loop.
Enabling which of the following feature will be able to prevent this problem from happening again?（）