Please check my answer thanks:)

You've been assigned to invite a group of mechanical engineering professor to tour your factory. What type of language should you use in the invitation?

Formal language

or Direct simple languge

I picked direct and simple

I agree, however, the purpose of the tour should be considered. For instance, if the tour was parcel to some type of future certification, I would go formal.

Thanks:)

Great! Picking direct and simple language for inviting a group of mechanical engineering professors to tour your factory is a good choice. Direct and simple language is often preferred for professional invitations as it is clear, concise, and easy to understand. It helps to communicate your message directly without any ambiguity or confusion. By using direct and simple language, you can effectively convey your invitation and encourage a positive response from the professors. Well done!