A. FileWriter类是Writer类的子类 B. FileWriter类是OutputStreamReader类的子类 C. FileWriter类是FileOutputStream类的子类 D. Wirter类是OutputStreamWriter类的子类
A. a1, a2 = new A(); B. a1 ,a2 = new(); C. a1 = new(); a2 = new(); D. a1 = new A(); a2 = new A();
A. abstract A {abstract void method()} B. class abstract B {abstract void method()} C. abstract class C {abstract void method()} D. abstract class D {abstract void method(){System.out.println(“d”)
A. 对 B. 错
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