Regardless of what type of expository text , any non-fiction text that aims to educate the reader, you are assigned to read, your primary comprehension goal is to identify the main point: the most important idea that the writer wants to communicate and often states early on. Finding the main point gives you a framework to organize the details presented in the reading and relate the reading to concepts you learned in class or through other reading assignments.
You need good comprehension to identify the main point it gives framework.