对于成员难以找到的总体(如城市中的散工、无家可归的流浪者和吸毒者)进行抽样,最合适的方法是()
A. 方便抽样
B. 雪球抽样
C. 配额抽样
D. 判断抽样
在网络预约出租汽车运营过程中,网络预约出租汽车驾驶员应携带《网络预约出租汽车运输证》和()。
A. 网络预约出租汽车驾驶员证
B. 居住证
C. 身份证
D. 驾驶证
public class A extends Thread { A() { setDaemon(true); } public void run() { (new B()).start(); try { Thread.sleep(60000); } catch (InterruptedException x) {} System.out.println(“A done”); } class B extends Thread { public void run() { try { Thread.sleep(60000); } catch (InterruptedException x) {} System.out.println(“B done”); } } public static void main(String[] args) { (new A()).start(); } } What is the result?()
A done
B done
C. A done B done
D. B done A done
E. There is no exception that the application will print anything.
F. The application outputs “A done” and “B done”, in no guaranteed order.