RELATIVE CLAUSES.

If you want to practice a bit more on relative clauses, here you have some links. You must have clear the difference between defining and non defining relative clauses and when the relative pronoun can be omitted and when it can't. So, here you have the links.
Revise for the test. Link # 1; Link #2; Link #3; Link #4; Link #5
If you have any doubts, don't hesitate and ask me!