From the reading of the text, we can conclude the following about the main idea of the sentence;
The main idea of this sentence is the fact that Judy Blume was an experienced writer who knew what she was doing. The many novels and articles that she has written over the years testify to her exceptional skills.
In the last sentence of the excerpt, we can also see a statement that directly and explicitly mentions this idea so that the reader can understand it. Thus, we can conclude that the idea is explicit because it is directly stated in the paragraph.
Learn more about explicit ideas here:
https://brainly.com/question/1853659
#SPJ1