Read the excerpts and decide if they are from a semi-formal or informal letter.

Choose the correct option.

The expression "Please accept my apologies for leaving the company" is from a [semi-formal letter|informal letter].

The expression "I'm afraid I will not be able to come on Saturday night" is from a [semi-formal letter |informal letter].

The expression "Why not call HR and ask them?" is from a [semi-formal letter |informal letter].