1. [第二题.png](https://image.zhihuishu.com/zhs/teacherExam_h5/COMMONUEDITOR/202104/06592c0884aa4e93ab1781243b5aaa14.png)![2B.png](https://image.zhihuishu.com/zhs/teacherExam_h5/COMMONUEDITOR/202104/a96d50ec572941f18c1e44a126876b1a.png)