You should review your emails before sending. Once they are sent you cannot get them back.

The correct choice is 'Sup?' because it is too informal and not appropriate for a professional email greeting.

The appropriate ways to begin an email to a teacher are 'Hi, Mr./Mrs...' and 'Good afternoon,'. These options show respect and professionalism.

When writing an email, the SUBJECT line should be a short description of what your email is about. This helps the recipient quickly understand the purpose of the email.

The correct choice is 'Polite' because a greeting should always be polite to show respect and kindness towards others.

The correct punctuation that should follow the polite greeting is a comma (,). It is used to separate the greeting from the rest of the sentence.

A closing salutation ('Sincerely', 'Thanks again', etc) should be included at the end of your email.