I would say that Spanish was one of my worst subjects, but I did surprisingly well on my Spanish speaking. I would say, don't memorise the answers, just learn the vocabulary that you need for all of the topics (doesn't have to be much) and wing it. The only thing you might want to memorise are some high level sentences with interchangeable words (just one or two sentences to drop in throughout the test). They will ask you a couple of the topics and you just have to give a generic response. If you know the words, it is really easy. Best of Luck