第1题:
Click the Exhibit button and examine the data in the EMPLOYEES table.On the EMPLOYEES table, EMPLOYEE_ID is the primary key. MGR_ID is the ID of managers and refers to the EMPLOYEE_ID. The JOB_ID column is a NOT NULL column.Evaluate this DELETE statement:DELETE employee_id, salary, job_idFROM employeesWHERE dept_id = 90;Why does the DELETE statement fail when you execute it?()

A.There is no row with dept_id 90 in the EMPLOYEES table.
B.You cannot delete the JOB_ID column because it is a NOT NULL column.
C.You cannot specify column names in the DELETE clause of the DELETE statement.
D.You cannot delete the EMPLOYEE_ID column because it is the primary key of the table.
第2题:
He always adopts () in face of difficulties.
Aa never saying die attitude
Ban attitude to say never die
Can attitude of saying never die
Dan attitude of never saying die
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are the reseason why the research was carried out
have something to do with their high rates of home births
suggest hospital birth is a better choice
have changed the government’s attitude towards home birth
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man has education but animal not
man is higher animal than any others
man is more susceptible to the environment than animals
after education, man will change permanently in the habits of behavior, thought and attitude
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He always adopts () in face of difficulties.
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