How to redirect to 404 page in htaccess?

Question

htaccess

Hello. Help me please.
I am currently facing this problem. Yandex Webmaster says that he indexes pages that he does not put in search results.
Pages of the format url.ru/section1/section11/section11.html
pages:

• url.ru/section1/section11/section11.html
  
• url.ru/section1/section11/
  

They have the same content. But I can’t figure out how to remove the section11.html postscript.
----
I also found several pages of the format
url.ru/section106/section106.html?section106.html&ection106.html&ection106.html
Please help