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?

Pollution of the ocean waters

Explanation:

The oceans have always been and still are the largest producers of oxygen on Earth. This is due to the enormous amount of producers that live in them. The producers have the ability to take the carbon dioxide out of the atmosphere, and release oxygen as a side product once they perform photosynthesis and respiration. The humans though use the oceans for dumping things in them, some of which are very dangerous, such as the oil spills, the plastic things, rubber, technological waste. They manage to hurt or even kill off the producers, thus reducing the intake of carbon dioxide from the atmosphere, and decrease the releasing of oxygen in it.

the answer is:

when will (v) the books (n) be (v) due?

nouns refer to people (other than pronouns), places and things, whereas verbs describe actions and are usually part of the predicate of a sentence. finally, pronouns can work as nouns and identify the participants in speech.

in the example sentence, "will" is a verb part or auxiliary verb, "be" is an infinitive verb and "books" is a plural noun.