Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE You issue these statements: CREATE table new_emp ( employe_id NUMBER, name VARCGAR2(30)); INSERT INTO new_emp SELECT employee_id, last_name from employees; Savepoint s1; UPDATE new_emp set name = UPPER(name); Savepoint s2; Delete from new_emp; Rollback to s2; Delete from new_emp where employee_id=180; UPDATE new_emp set name = 'James'; Rollback to s2; UPDATE new_emp sey name = 'James' Where employee_id=180; Rollback; At the end of this transaction, what is true?（）
A、You have no rows in the table.
B、You have an employee with the name of James.
C、You cannot roll back to the same savepoint more than once.
D、Your last update fails to update any rows because employee ID 180 was already deleted.
After a baseline check was completed it was noted that the network was working far below the level of the last baseline. Which of the following should the technician do NEXT to determine where the network problems are occurring?（）
A、Upgrade the firmware on all routers and switches
B、Reboot the entire network one device at a time
C、Conduct a network traffic analysis
D、Rerun the baseline to ensure the results were correct
产品树中的根结点应是产品的（）。
A、效果图
B、示意图
C、装配简图
D、装配图
绘制轴测剖视图的方法有先画（）再作剖视和先画断面形状，再画投影两种。
A、主视图
B、透视图
C、剖切面
D、外形
Which of the following cable types has a MAXIMUM transmission speed of 10Mbps?（）
A、CAT6
B、CAT5
C、Single-mode fiber
D、CAT3
选择性