单项选择题
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.
单项选择题 Which code， inserted at line 14， will allow this class to correctly serialize and deserialize？（）
单项选择题 Given that the current directory is empty， and that the user has read and write permissions， and the following： Which statement is true？（）
单项选择题 Whichcapabilityexistsonlyinjava.io.BufferedWriter？（）
