采用直流供电的电动变桨矩系统中（）部件不是按桨叶独立配置。 轴控柜。 电池柜。 主控柜。 直流电机。
Which four are true？（） Has-a relationships should never be encapsulated.。 Has-a relationships should be implemented using inheritance.。 Has-a relationships can be implemented using instance variables.。 Is-a relationships can be implemented using the extends keyword.。 Is-a relationships can be implemented using the implements keyword.。 An array or a collection can be used to implement a one-to-many has-a relationship.。 The relationship between Movie and Actress is an example of an is-a relationship.。
车用汽油的90%馏出温度和干点有何意义？
曝气生物滤池反冲洗系统由哪些组成？其目的是什么？
Which two are true about has-a and is-a relationships？（） Inheritance represents an is-a relationship.。 Inheritance represents a has-a relationship.。 Interfaces must be used when creating a has-a relationship.。 Instance variables can be used when creating a has-a relationship.。
下列关于"行为"面板的说法中错误的是（）
