What is a good example of a discourse community topic?

In researching his history report about the civil war, why is ariq most likely to use secondary data than primary data?

Match the definition to the term. 1. pronouns or verbs used to show the person speaking, the person spoken to person 2. a form of noun, pronoun, or adjective used to show its relation to other words gender 3. the grouping of nouns into the classes masculine, feminine, and neuter case 4. an inflection or word form that shows whether one or more than one is meant number 5. pronouns that show by their form personal pronouns

Oceans produce approximately 80 percent of the oxygen our planet needs to support animal life. pollution that reaches the ocean through dumping, oil leaks, runoff, and other processes interferes with that oxygen production and poses a real threat to the oxygen content in our atmosphere. if the oxygen content decreases, it is likely that carbon dioxide will increase. this could have dramatic consequences for life as we know it. which does this passage indicate causes a decrease of oxygen in the atmosphere?