单项选择题
Given： What is the result？（）
A.Compilation fails. B.An exception is thrown at runtime. C.An instance of Forest is serialized. D.An instance of Forest and an instance of Tree are both serialized.
Given： What is the result？（）A.7B.49C.343D.Compilation ...
A.7 B.49 C.343 D.Compilation fails. E.An exception is thrown at runtime.
Given： Which code fragment， inserted at line 23， allow...
Given： Which code fragment， inserted at line 23， allows the code to compile？（）
A.df = new DateFormat（）； B.df = Date.getFormat（）； C.df = date.getFormat（）； D.df = DateFormat.getFormat（）； E.df = DateFormat.getInstance（）；
Given： What is the result？（）A.CanadaB.null CanadaC.Can...
A.Canada B.null Canada C.Canada null D.Canada Canada E.Compilation fails due to an error on line 26. F.Compilation fails due to an error on line 29.
