Hello,
if you want extra exercises to practise  for the exam go to the following links:

much, many, a lot of:

http://www.ejerciciodeingles.com/expresiones-cantidad-ingles-a-lot-of-much-many/
http://lawebdelingles.com/nivel-a1/como-se-usa-much-many-y-a-lot-of/ explanation in Spanish

One/ones


http://www.englisch-hilfen.de/en/exercises/nouns_articles/one.htm
https://learnenglish.britishcouncil.org/es/english-grammar/pronouns/one-and-ones

Good luck.