AP计算机教程3-8：困难多选题

Given the following code segment, which of the following is true?

String s1 = new String("Hi There");
String s2 = new String("Hi There");
String s3 = s1;

I. s1 == s2
II. s1.equals(s2)
III. s1 == s3
IV. s2.equals(s3)

What does the following code print?

System.out.println("13" + 5 + 3);