假设给定如下语句 选项中哪些语句或表达式是错误的: String s1 = Welcome to Java; String S2 = Programming is fun;

假设给定如下语句,选项中哪些语句或表达式是错误的: String s1 = "Welcome to Java"; String S2 = "Programming is fun";

A、String s3 = s1 + s2;

B、String s3 = s1 - s2;

C、s1 == s2;

D、s1 >= s2;

E、s1.compareTo-1);