混凝土刚性防水屋面的防水层应采用不低于()级的细石混凝土整体现浇。 C30。 C25。 C20D。 C15。
For which action can you use the TO_DATE function? () Convert any date literal to a date。 Convert any numeric literal to a date。 Convert any character literal to a date。 Convert any date to a character literal。 Format '10-JAN-99' to 'January 10 1999'。
“后茶馆式”教学中的“做”是增加学生的经验。这种学生的学习经历不仅增加了学生自身的默会知识,而且可以进一步产生()的对话。
User SCOTT executes the following command on the EMP table but has not issued COMMIT, ROLLBACK,or any data definition language (DDL) command: SQL> SELECT job FROM emp 2 WHERE job=’CLERK’ FOR UPDATE OF empno; SCOTT has opened another session to work with the database. Which three operations would wait when issued in SCOTT’s second session?() LOCK TABLE emp IN SHARE MODE;。 LOCK TABLE emp IN EXCLUSIVE MODE;。 DELETE FROM emp WHERE job=’MANAGER’;。 INSERT INTO emp(empno,ename) VALUES (1289,’Dick’);。 SELECT job FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno;。
在平视情况下,用高花盆插S形,选用()。 倾斜式S形。 下垂式S形。 平卧式S形。 对称式S形。
对于新产品开发来说,项目的成果是()。