User-agent: Mediapartners-Google*
Disallow:

User-agent: Googlebot
Disallow: /ads/
Disallow: /rateit/
Disallow: /bitrix/
Disallow: /by-tag/

User-agent: *
Disallow: /ads/
Disallow: /rateit/
Disallow: /bitrix/
Disallow: /by-tag/