A.13
B.134
C.1234
D.2134
E.2143
F.4321

A.int foo（）{/* more code here */}
B.void foo（）{/* more code here */}
C.public void foo（）{/* more code here */}
D.private void foo（）{/* more code here */}
E.protected void foo（）{/* more code here */}

A.Cat is-a Animal
B.Cat is-a Jumper
C.Dog is-a Animal
D.Dog is-a Jumper
E.Cat has-a Animal
F.Beagle has-a Tail
G.Beagle has-a Jumper

A.420 is the output.
B.An exception is thrown at runtime.
C.All constructors must be declared public.
D.Constructors CANNOT use the private modifier.
E.Constructors CANNOT use the protected modifier.

A.Inheritance
B.Low cohesion
C.Tight coupling
D.High cohesion
E.Loose coupling
F.Object immutablility

A.Compilation fails.
B.An exception is thrown at runtime.
C.doStuff x=6，main x=6
D.doStuff x=5，main x=5
E.doStuff x=5，main x=6
F.doStuff x=6，main x=5

A.81
B.82
C.91
D.92
E.Compilation fails.
F.An exception is thrown at runtime.

A.Looser coupling
B.Tighter coupling
C.Lower cohesion
D.Higher cohesion
E.Weaker encapsulation
F.Stronger encapsulation

A.class Man extends Dog{}
B.class Man implements Dog{}
C.class Man{private BestFriend dog；}
D.class Man{private Dog bestFriend；}
E.class Man{private Dog；}
F.class Man{private BestFriend；}

A.Change line 2 to：public int a；
B.Change line 2 to：protected int a；
C.Change line 13 to：public Sub（）{this（5）；}
D.Change line 13 to：public Sub（）{super（5）；}
E.Change line 13 to：public Sub（）{super（a）；}