Problem: Does the researcher identify how the study will address any gaps in knowledge Answer: Yes, the researchers identify what is known and not known about the problem in the article. Explanation: In research articles, particularly those involving clinical trials, it is common for authors to provide a background or literature review section that outlines the current state of knowledge regarding the research topic. This section typically includes what is already known about the problem, such as previous findings on the effects of omega-3 fatty acids on mental health, and highlights gaps in the existing research that the current study aims to address. In the article by Paduchová et al. (2021), the authors likely discuss the known effects of omega-3 fatty acids on depressive symptoms and related biomarkers, as well as the specific aspects that remain unclear or under-researched, such as their impact on thromboxane, brain-derived neurotrophic factor, homocysteine, and vitamin D levels in depressive children and adolescents. This helps to establish the rationale for conducting the study and the significance of their research findings. Need Online Tutoring?