These days, we are learning or revising Relative Clauses in English, they are also called Defining and Non-defining relative clauses. As you well know, you must practise them a lot before taking the exam, and also, now you can use these new structures in your compositions. So, I recommend you to click on the following links, they are truly useful!!!
1. inglescarmelitas (theory + exercises)
2. autoenglish.org (theory + exercises + key answers)
3. Relatives (exercises + key answers)
4. eoimanresa (exercises + key ansers)
5. bachiller.sabuco (exercises)
6. iesdamasoalonso (exercises + key answers)
Besides, if you click on the label Relatives (on the right side), other posts related to this will be displayed.