Given a vaid DateFormat object named df， and

What updates d’s value with the date represented by ds？（）

多项选择题Giventhatcisareferencetoavalidjava.io.Consoleobject，whichtwocodefragmentsreadalineoftextfromtheconsole？（）

A.String s = c.readLine（）；
B.char[ ] c = c.readLine（）；
C.String s = c.readConsole（）；
D.char[ ] c = c.readConsole（）；
E.String s = c.readLine（"%s"， "name "）；
F.char[ ] c = c.readLine（"%s"， "name "）；

多项选择题Whichthreestatementsconcerningtheuseofthejava.io.Serializableinterfacearetrue？（）

A.Objects from classes that use aggregation cannot be serialized
B.An object serialized on one JVM can be successfully deserialized on a different JVM
C.The values in fields with the volatile modifier will NOT survive serialization and deserialization
D.The values in fields with the transient modifier will NOT survive serialization and deserialization
E.It is legal to serialize an object of a type that has a supertype that does NOT implement java.io.Serializable

单项选择题Given that the current directory is empty， and that the user has read and write privileges to the current directory， and the following： Which statement is true？（）

A.Compilation fails.
B.Nothing is added to the file system.
C.Only a new file is created on the file system.
D.Only a new directory is created on the file system.
E.Both a new file and a new directory are created on the file system.

单项选择题If the user types the password aiko when prompted， what is the result？（）

A.password：got
B.password：got aiko
C.password：aiko；got aiko
D.An exception is thrown at runtime.
E.Compilation fails due to an error on line 8.

单项选择题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.