In my opinion, vocabulary is the key to language learning, and it's the key to a good IELTS score. The more words and phrases you know, the better you'll do in the test.
Have you made note of all the vocabulary in this week's lessons here on the site? Look closely at the lessons and you'll find a lot of useful language. Write it down in your notebook, and try using it.
If anyone could write a summary of this week's useful vocabulary in the "comments" below this lesson, that would be great!