User-agent: Mediapartners-Google 
Disallow:
User-agent: Baiduspider
User-agent: Baiduspider-video
User-agent: Baiduspider-image
Disallow: /
User-agent: AhrefsBot 
Disallow: /
User-agent: SemrushBot
Disallow: /
User-agent: SemrushBot-SA
Disallow: /

User-agent: MJ12bot
Disallow: /