屋面防水等工程施工完成后必须保证足够的排水坡度（1.5%-3%），确保排水顺畅。不得有积水、（）现象。 漏气。 漏水。 渗漏。 漏电。
职工应当参加基本养老保险，由用人单位和职工共同缴纳基本养老保险费。公务员和参照公务员法管理的工作人员养老保险的办法按照企业参加基本养老保险规定执行。
You have a production instance running on your server. UNDO_RETENTION is not long enough to satisfy read-consistency requirements. How do you change the UNDO_RETENTION value？（） A。 B。 C。 D。
Examine the data in the EMPLOYEES and EMP_HIST tables: EMPLOYEES NAME DEPT_ID MGR_ID JOB_ID SALARY EMPLOYEE_ID 101 Smith 20 120 SA_REP 4000 102 Martin 10 105 CLERK 2500 103 Chris 20 120 IT_ADMIN 4200 104 John 30 108 HR_CLERK 2500 105 Diana 30 108 IT_ADMIN 5000 106 Smith 40 110 AD_ASST 3000 108 Jennifer 30 110 HR_DIR 6500 110 Bob 40 EX_DIR 8000 120 Ravi 20 110 SA_DIR 6500 EMP HIST EMPLOYEE_ID NAME JOB_ID SALARY 101 Smith SA_CLERK 2000 103 Chris IT_CLERK 2200 104 John HR_CLERK 2000 106 Smith AD_ASST 3000 108 Jennifer HR_MGR 4500 The EMP_HIST table is updated at the end of every year. The employee ID, name, job ID, and salary of each existing employee are modified with the latest data. New employee details are added to the table. Which statement accomplishes this task?（） UPDATE emp_hist SET employee_id, name, job_id, salary = (SELECT employee_id, name, job_id, salary FROM employees) WHERE employee_id IN (SELECT employee_id FROM employees);。 MERGE INTO emp_hist eh USING employees e ON (eh.employee_id = e.employee_id) WHEN MATCHED THEN UPDATE SET eh.name = e.name, eh.job_id = e.job_id, eh.salary = e.salary WHEN NOT MATCHED THEN INSERT VALUES (e.employee id, e.name, job id, e.salary);。 MERGE INTO emp_hist eh USING employees e ON (eh.employee_id = e.employee_id) WHEN MATCHED THEN UPDATE emp hist SET eh.name = e.name, eh.job_id = e.job_id, eh.salary = e.salary WHEN NOT MATCHED THEN INSERT INTO emp_hist VALUES (e.employees_id, e.name, e.job_id, e.salary);。 MERGE INTO emp_hist eh USING employees e WHEN MATCHED THEN UPDATE emp_hist SET eh.name = e.name, eh.job_id = e.job_id, eh.salary = e.salary WHEN NOT MATCHED THEN INSERT INTO emp_hist VALUES (e.employees_id, e.name, e.job_id, e.salary)。
张某，男性，40岁，劳动时不慎，左足被刺破，伤口处皮肤出现红线，并向近心端延伸，触及发硬并有压痛，最可能是（） 浅静脉炎。 深静脉炎。 淋巴结炎。 浅表淋巴管炎。 深部淋巴管炎。
从根本上说，税收的存在是由（）决定的。
