------
## 最终结论
```python
def specified_element(two_d_list, index):
    result = []
    for row in two_d_list:
        result.append(row[index])
    return result

# Test cases
assert specified_element([[1, 2, 3, 2], [4, 5, 6, 2], [7, 1, 9, 5]],0) == [1, 4, 7]
assert specified_element([[1, 2, 3, 2], [4, 5, 6, 2], [7, 1, 9, 5]],2) == [3, 6, 9]
assert specified_element([[1, 2, 3, 2], [4, 5, 6, 2], [7, 1, 9, 5]],3) == [2,2,5]
```