1. class Synapse { 2. protected int gap() { return 7; } 3. } 4. 5. class Creb extends Synapse { 6. // insert code here 7. } 分别插入到第 6 行,哪三行可以编译?()
A. int gap() { return 7; }
B. public int gap() { return 7; }
C. private int gap(int x) { return 7; }
D. protected Creb gap() { return this; }
E. public int gap() { return Integer.getInteger ("42"); }