In the SQL language, the command to delete all the data in a table but keep the table structure is ()
A. DELETE
B. DROP
CLEAR
D. REMORE
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A function used to find the date of a system is ( )
A. YEAR()
B. GETDATE()
COUNT()
D. SUM()
which one is wrong( )。
A. select right('hello',3)return value=hel
B. select ltrim(rtrim(' hello '))return value=hello (without spaces)
C. select replace('hello','e','o') return value=hollo
D. select len('hello') return value=5
对存在语言发展障碍的儿童来说,进行语言矫治的关键期是( )
A. 婴儿期
B. 学前期
C. 学龄期
D. 学龄中期
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