Pay for someone to write a Python 3 function that returns its HTML from a URL.

admin

```python
import requests
def get_html(url):
    response = requests.get(url)
    if response.status_code == 200:
        return response.text
    else:
        return None
# 测试用例
url = 'https://www.sehuatang.org/forum-2-1.html'
print(get_html(url))
```