Dear John,
Thank you got the invitation, but don’t you think going to the zoo can be a little bit boring. Also, there are a lot of programmers about animals on TV. You can see them at any time you want. And get acquainted with the developments of science you can only in the museum. Let’s go to the zoo next time, because I-ve two tickets to science museum:)
See you soon,
Gskgak
(Немного не уложился в объеме, сам/а сократишь что не понравилось)