给出下面的类: public class Sample{ long length; public Sample(long x){ length = x; } publi
给出下面的类: public class Sample{ long length; public Sample(long x){ length = x; } public static void main(String arg[ ]){ Sample s1, s2, s3; s1 = new Sample(21L); s2 = new Sample(21L); s3 = s2; long m = 21L; } } 下面表达式中返回false的是()。
A、s1 == s2
B、s2 == s3
C、m == s1
D、s1.equals(m)