This particular grammar practice worksheet has a short passage about scientific inquiry. The questions below the passage address specific sentences (numbered) in the passage and ask students to evaluate whether the sentence is a complete thought, fragment, or run-on. Several questions also ask students to select the best way to re-write the sentences, or whether they should be left as is. This is very much in line with state standardized testing format for writing/grammar skills. This sheet can be used as classwork practice, homework, or even as a graded assignment if you've already been practicing together on other sheets.