[单选题]Examine the structure of the EMPLOYEES table:EMPLOYEE_ID NUMBER Primary KeyFIRST_NAME VARCHAR2(25)LAST_NAME VARCHAR2(25)HIRE_DATE DATEWhich UPDATE statement is valid?()A . UPDATE employees SET first_name = 'John' SET last_name ='Smith'
[单选题]小说《潘先生在难中》的作者是()A . 叶圣陶B . 许地山C . 郁达夫D . 朱自清