Strings & Patterns Learning Mode

Which of these regex expressions will identify both e-mail addresses (and only the e-mail addresses) in the following text. Pick as many as apply.

" Knock over christmas tree stare at ittens@catsaregreat.com the wall, play with food and get confused by dust or going to catch siamese@catsaregreat.com the red dot today going to catch the red dot today.".