Identify the type of subordinate clause in the following sentence. the trouble was that he forgot where he put his keys. noun adjective adverb

Which statement is not true about run-on sentences? a. a run-on sentence has more than one clause. b. one way to correct a run-on sentence is to add a joining word c. one way to correct a run-on sentence is to add an appropriate punctuation mark. d. a run-on sentence has only one clause.