Which number marks a run-on sentence-a group of words made up of two sentences

Which statement best supports the author's purpose in "children of the drug wars," which is to persuade readers that the united states should do more to immigrant children from honduras?

What language device is used in the highlighted text?

Dogs make wonderful pets because they keep us happy and healthy, the topic sentence is "dogs make wonderful pets". can someone me write a unrelated sentences to the topic and can be eliminated. need asap