I do not agree: you should always specify the version. An old version (eg mssql 2005) can be still alive and diffused.

It should be underlined that this

[font="Courier New"]DECLARE @str VARCHAR(8000) = N'SELECT * FROM sys.objects'

EXECUTE SP_EXECUTESQL @str[/font]

works on MSSQL 2008 -->

On MSSQL 2005 it returns

[font="Courier New"]Msg 139, Level 15, State...