use file to open and get contents into an array.
use count to get number of lines/words
use srand and rand to get a random number.
modulo it with the count above to get final random number.
use this final random number with the array to get the string

now use the google api, to search and retirieve results. (google has source code available of how to use its api with php)

a thought: you might not want to build such useless pages, 'coz people dont need them. if you are looking for advertising or adsense $$$, i will like to tell you that google will come heavily on you, so better not to do something silly like this.
google/other search engines are modifying their algo's to penalize such size/pages heavily...

Thanks, for your help Jayant,

Great solution but i am a totally newbee coding or programming such a php script. Are there any easier solultions?

I don`t want to build such useless pages to cheat google adsense?
But thanks for the info!