4. Which two statements are true regarding single row functions? (Choose two.)
A. They a ccept only a single argument.
B. They c an be nested only to two levels.
C. Arguments can only be column values or constants.
D. They always return a single result row for every row of a queried table.
对于查询表的每一行总是返回一个结果行.正确。
E. They can return a data type value different from the one that is referenced.
返回的数据类型值可以与之前引用的数据类型不同，正确。
Answer: DE