Question

What should be written in formal style?

personal e-mails
friendly letters
movie reviews
work documents​

Answer 1

Movie reviews and Work documents.

Step-by-step explanation:

Because, Movie reviews and Work documents will be seen by people you are not familiar with and you would benefit from speaking formally to come off as polite.

Answer 2

Work documents.

Step-by-step explanation:

Work documents are normally for your colleagues, manager and company related. Personal e-mails are for your family members, movie reviews don't really have to be formal and friendly letters are meant to be informal.