单项选择题
A. The Mycircle class is fully encapsulated.
B. The diameter of a given MyCircle is guaranteed to be twice its radius.
C. Lines 6 and 7 should be in a synchronized block to ensure encapsulation.
D. The radius of a MyCircle object can be set without affecting its diameter.
多项选择题 class BaseClass{ private float x= 1.0f； protected void setVar （float f） {x = f；} } class SubClass extends BaseClass { private float x = 2.0f； //insert code here } Which two are valid examples of method overriding？（）
单项选择题 1. class A implements Runnable ( 2. int i; 3. public void run () ( 4. try ( 5. thread.sleep(5000); 6. i= 10; 7. ) catch(InterruptedException e) {} 8. ) 9. ) 10. 11. public class Test { 12. public static void main (string args[]) ( 13. try ( 14. A a = new A (); 15. Thread t = new Thread (a); 16. t.start(); 17. 18. int j= a.i; 19. 20. ) catch (Exception e) {} 21. ) 22. } Which statement al line 17 will ensure that j=10 at line 19？（）
单项选择题 Whichmethodisanappropriatewaytodeterminethecosineof42degrees？（）