How to pass a value from .cs file to HTML or .aspx page using normal HTML tags

I wish to pass some values retrieved from SQL DB to a page, the page is designed without ASP tools, and I wish to pass some values to be displayed on the page, but can't do it yet : \

this is an example:

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string x = "hello from .cs";
    }
}

<p class="some class">Here comes the x value from .cs