Can someone please explain to my why this is an independent clause this James Lu person said it is. that the ancient ruins held secrets lost to time fascintaed archaeologists for centuries It just doesn't sound right but I understand why it can be an independent clause but I dont see why he couldn't just start it off with "The idea" and remove the "the"

Hello, I am a 13+ year old eighth(almost ninth grader) that wants to start studying for the SAT. How should I study and what should I start with. I just finished Algebra 1, and I have been studying Geometry during the summer. My English level is not the best, but my ELA teacher was strict about grammar and passages. He took off like 5 points per grammar mistakes, such as comma mistakes, proper formats, and more. He took off 15 points if there is a easier way to explain something. My grades were terrible during the first quarter. The essay projects and homework were destroying my grades. Eventually, I became a straight A student again. I improved my English, but I definitely struggle more on English than Math.