多项选择题
A.When using versions of Java technology earlier than 5.0.
B.When sharing a StringBuffer among multiple threads.
C.When using the java.io class StringBufferInputStream.
D.When you plan to reuse the StringBuffer to build more than one string.
单项选择题 Given： 12.Date date = new Date（）； 13.df.setLocale（Locale.ITALY）； 14.String s = df.format（date）； The variable df is an object of type DateFormat that has been initialized in line 11. What is the result if this code is run on December 14， 2000？（）
单项选择题 Given： What is the result？（）
单项选择题 Given： Which statement is true？（）