多选题 Given:
2. interface Clickable {void click(); }
3. // insert code here
Which code, inserted independently at line 3, will compile? (Choose all that apply.)

A、 interface Keyboard extends Clickable { }
B、 interface Keyboard extends Clickable {void click(); }
C、 interface Keyboard extends Clickable {void doClick(); }
D、 interface Keyboard extends Clickable {void click() { ; } }
E、 interface Keyboard extends Clickable {protected void click(); }
F、 interface Keyboard extends Clickable {void click(); void doClick(); }

【正确答案】 A、B、C、F

【答案解析】