What does "affluent" mean?
or I would use the "insert correct word into the sentence" method:
It was clear that he was very ............. because he had a very large house and an expensive car.
I also sometimes did an oral test where I would give my student a list of all the vocabulary we learnt in the previous lesson, then start a random conversation and the student had to use each word at least once in the conversation. I ticked them off the list as we went. Of course, the student had to use the word correctly, appropriately and with the correct pronounciation and stress.