80. Which two statements are true regarding working with dates? (Choose two.)
A. The default internal storage of dates is in the numeric format.
B. The default internal storage of dates is in the character format.
C. The RR date format automatically calculates the century from the SYSDATE function and does not
allow the user to enter the century.
D. The RR date format automatically calculates the century from the SYSDATE function but allows the
user to enter the century if required.
Answer: AD答案解析：
AB,默认内部日期的存储形式是数字形式,所有A对，B错。
A参照Database Concepts的DATE Data Type部分：
The database stores dates internally as numbers. Dates are stored in fixed-length fields of 7 bytes each, corresponding to century, year, month, day, hour, minute, and second
CD,RR日期格式自动从SYSDATE函数中计算出世纪，但是如果需要还允许用户输入世纪,所有C错，D对。