What are the answer choices?
Answer: Most space debris is created when satellites collide or explode.
Answer: In the research context, the term validity most commonly refers to whether a project is <em>based ion truth or reason and indicates how sound a</em> <em>research is.</em> <em>Validity claims are solid claims that represent the truth.</em> Also, it refers to how well an instrument measures what it intended to measure. A survey that aims to measure depression but actually measures anxiety would not be considered valid.
I don't really understand what u r asking but centeral idea is main idea if that's what u r asking...
