Explanation: "Since the Wright brothers made their first flight in 1903, flying developed relatively early" is an example of a complex sentence. Complex sentences are formed by an independent clause, that can stand on its own, as the second part of the example, and one or more dependent clauses added that cannot stand on their own as a sentence, for example the first part of the sentence given.
hey killing yourself is NEVER the solution to anything. If your parents call you a dissapointment, the prove them that they are wrong. If you think that you are going to fail your 7th grade, then study harder and get help from your friends or teachers. Don't be aftraid to ask help from them. Btw, success comes from failure.
