It is always important to find multiple news sources related to the topic you're writing about so that you have access to more accurate information on your topic, and you will also earn the beneficial experience of hearing the viewpoints of others so that you can develop your own; doing this will also make your writing sound clearer and more precise. The more news sources you use, the more reliable your writing will be.
Answer: Seeking only one source can give a one-sided, biased perspective on a topic.