How does Baidu show my ads?

Currently, Baidu displays paid search ads in the following three ways:

Above the organic results, unhighlighted

Baidu ads unhighlighted

Above the organic results, highlighted

Baidu ads highlighted

Above the organic results, but under the branded ads

Under Baidu branded ads

Occasionally Baidu displays the ads on the right sidebar, but we see that less and less nowadays, especially on the first page of the search results.