Try these exercises for the grammar and vocabulary practice on Passive Voice and Shopping:

 

Brg2 AIO More Practice 3

Brg2 AIO Reinforce 3

brg2-aio-more-prac-3-ak

You’ll find a plethora of exercises on this page:

http://www.agendaweb.org/verbs/passive-exercises.html

And a more complete explanation about Passive Voice on this link:

http://roble.pntic.mec.es/dgub0004/passive.html