多选题 Given the proper import(s), and given:
13. class NameCompare implements Comparator＜Stuff＞ {
14. public int compare(Stuff a, Stuff b) {
15. return b.name.compareTo(a.name);
16. } }
18. class ValueCompare implements Comparator＜Stuff＞ {
19. public int compare(Stuff a, Stuff b) {
20. return (a.value - b.value);
21. } }
Which are true? (Choose all that apply.)

A、 This code does not compile.
B、 This code allows you to use instances of Stuff as keys in Maps.
C、 These two classes properly implement the Comparator interface.
D、 NameCompare allows you to sort a collection of Stuff instances alphabetically.
E、 ValueCompare allows you to sort a collection of Stuff instances in ascending numeric order.
F、 If you changed both occurrences of "compare()" to "compareTo()", the code would compile.

【正确答案】 C、E

【答案解析】