A programmer has an algorithm that requires a java.util.List that provides an efficient implementation of add(0, object), but does NOT need to support quick random access. What supports these requirements?（）

单项选择题Given the following directory structure: bigProject |--source | |--Utils.java | |--classes |-- And the following command line invocation: javac -d classes source Utils.java Assume the current directory is bigProject,what is the result? （）

A.If the compile is successful, Utils.class is added to the source directory.
B.The compiler returns an invalid flag error.
C.If the compile is successful, Utils.class is added to the classes directory.
D.If the compile is successful, Utils.class is added to the bigProject directory.

单项选择题Click the Exhibit button. Given the fully-qualified class names: com.foo.bar.Dog com.foo.bar.blatz.Book com.bar.Car com.bar.blatz.Sun Which graph represents the correct directory structure for a JAR file from which those classes can be used by the compiler and JVM? （）

A.Jar A
B.Jar B
C.Jar C
D.Jar D
E.Jar E

多项选择题Click the Exhibit button. Which three code fragments, added individually at line 29, produce the output 100?（）

A.n = 100;
B.i.setX( 100 );
C.o.getY().setX( 100 );
D.i = new Inner(); i.setX( 100 );
E.o.setY( i ); i = new Inner(); i.setX( 100 );
F.i = new Inner(); i.setX( 100 ); o.setY( i );

单项选择题Given: What is the result?（）

A.Compilation fails.
B.exception is thrown at runtime.
C.The attribute id in the ItemTest object remains unchanged.
D.The attribute id in the ItemTest object is modified to the new value.
E.A new ItemTest object is created with the preferred value in the id attribute.

多项选择题Which two scenarios are NOT safe to replace a StringBuffer object with a StringBuilder object?（）

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.