A、sum=10 B、sum=70 C、sum=60 D、运行时抛出异常
A、∑X=0,∑Y=0,∑Mx=0 B、∑X=0,∑Y=0,∑My=0 C、∑X=0,∑Y=0,∑Mz=0 D、∑X=0,∑Z=0,∑Mz=0
A、public int sum(int a, int b) { return a + b; } B、public int sum(long a, long b) { return 0; } C、abstract int sum(); D、private long sum(long a, long b) { return a + b; } E、public long sum(long a, int b) { return a + b; }