Don't be afraid to express your own views
Many students are hesitant about expressing their own opinion, particularly if it contradicts the views of 'experts'. Work that is published and printed in books and learned journals is not necessarily always right nor the very last word on a topic. In the humanities and social sciences in particular, much academic writing is based on informed opinion rather than indisputable fact. Do not be afraid to have your own views on a subject. What is important is that your views should be informed, clearly expressed and based on careful consideration and knowledge of both the relevant facts and of the views of those who are acknowledged to have expertise on the topic.
It may be much more difficult for science students to have new ideas or make original contributions to their subject in the early stages of their scientific education. What you can show in your writing is that you are aware of all the relevant information, and have a full knowledge and understanding of the scientific principles that underpin the experiments that you write up or the reports that you complete. When you carry out an experiment, the method you use is perhaps unlikely to be your own, and you may well need to acknowledge the source of the particular methodology you employ. However, the results that you obtain when you carry out the experiment are your own, and in their analysis and interpretation you can make your own contribution.