单项选择题
Given: Which code, inserted at line 4, guarantees that this program will output [1, 2]（）?
A.Set set = new TreeSet(); B.Set set = new HashSet(); C.Set set = new SortedSet(); D.List set = new SortedList(); E.Set set = new LinkedHashSet();
多项选择题 Given a class whose instances, when found in a collection of objects, are sorted by using the compareTo()method, which two statements are true?（）
单项选择题 Given: What is the result?（）
