1. Acumen. (n.d.). In Collins dictionary.https://www.collinsdictionary.com/dictionary/english/acumen
2. Alertness. (n.d.). In Wikipedia.https://en.wikipedia.org/wiki/Alertness
3. Aptitude. (n.d.). In Teachmint.https://www.teachmint.com/glossary/a/aptitude-meaning/
4. Astuteness. (n.d.). In Dictionary.https://www.dictionary.com/browse/astuteness
5. Brain. (n.d.). In Encyclopaedia Britannica.https://www.britannica.com/science/brain