------
## 最终结论
```python
def check_element(lst, string):
    return all(element == string for element in lst)

# Test cases
assert check_element(["green", "orange", "black", "white"],'blue')==False
assert check_element([1,2,3,4],7)==False
assert check_element(["green", "green", "green", "green"],'green')==True
```