Explanation: When researching a topic, we need to be careful with the sources that we use. According to the topic that we are researching, we need to find the most reliable sources, because in this way, we can be sure that the information that we obtain, is correct and trust worthy. If we are looking for information about tornadoes in the United States, the most credible source would be a government agency's weather website.
Often, root words are used in the making of new words. The word created from it will have meanings related to its root word, which allows one to get an idea of what the unfamiliar word could mean.