------
## 最终结论
```python
def check_Consecutive(lst):
    if len(lst) <= 1:
        return True
    lst.sort()
    for i in range(1, len(lst)):
        if lst[i] - lst[i - 1] != 1:
            return False
    return True

# Test cases
assert check_Consecutive([1,2,3,4,5]) == True
assert check_Consecutive([1,2,3,5,6]) == False
assert check_Consecutive([1,2,1]) == False
```