Given:

Which code, inserted at line 15, creates an instance of the Point class defined in Line?（）

单项选择题Given: Which statement is true?（）

A.The code will compile without changes.
B.The code will compile if public Tree() { Plant(); } is added to the Tree class.
C.The code will compile if public Plant() { Tree(); } is added to the Plant class.
D.The code will compile if public Plant() { this("fern"); } is added to the Plant class.
E.The code will compile if public Plant() { Plant("fern"); } is added to the Plant class.

单项选择题Click the Exhibit button. Given: ClassA a = new ClassA(); a.methodA(); What is the result? （）

A.Compilation fails.
B.ClassC is displayed.
C.The code runs with no output.
D.An exception is thrown at runtime.

单项选择题Given: What is the result?（）

A.harrier
B.shepherd
C.retriever
D.Compilation fails.
E.retriever harrier
F.An exception is thrown at runtime.

单项选择题Given: If some sort of exception is thrown at line 34, which output is possible?（）

A.a
B.b
C.c
D.ac
E.abc

单项选择题Given: Which code, inserted at line 16, will cause a java.lang.ClassCastException?（）

A.Alpha a = x;
B.Foo f = (Delta)x;
C.Foo f = (Alpha)x;
D.Beta b = (Beta)(Alpha)x;