多选题Which four statements are true？（）AHas-a relationships should never be encapsulated.BHas-a relationships should be implemented using inheritance.CHas-a relationships can be implemented using instance variables.DIs-a relationships can be implemented usin
题目
多选题
Which four statements are true？（）
A
Has-a relationships should never be encapsulated.
B
Has-a relationships should be implemented using inheritance.
C
Has-a relationships can be implemented using instance variables.
D
Is-a relationships can be implemented using the extends keyword.
E
Is-a relationships can be implemented using the implements keyword.
F
An array or a collection can be used to implement a one-to-many has-a relationship.