在set接口中使用哪个方法查询元素数() A: clear() B: addAll() C: size() D: visitDeclared()

阅读代码，选择正确答案。 import java.util.*; public class TestListSet{ public static void main(String args[]){ List list = new ArrayList(); list.add(“Hello”); ist.add(“Learn”); list.add(“Hello”); list.add(“Welcome”); et set = new HashSet(); set.addAll(list); System.out.println(set.size()); } }

以下哪些是List提供的增加元素的方法？ A: add() B: addLast() C: addAll() D: addFirst()

Collection接口中，进行集合的批量删除的方法是________。 A: addAll() B: add() C: removeAll () D: containsAll()

在Collection接口中，对集合进行批量增加的方法是________。 A: addAll() B: add() C: removeAll() D: remove()

下列哪一个方法没有在Collection中定义 A: oolean addAll(Collection c) B: oolean isEmpty() C: Object[] toArray() D: emove(int index)

The rain looked as though it had ______for the night. A: set off B: set in C: set out D: set up

The sun ______ in the west. A: sets B: will set C: set D: is going to set

A new school has been _____there. A: set out B: set off C: set up D: set down

The government has _____a committee to inquire into the problem. A: set aside B: set out C: set up D: set about