It's "computers", because they're the subject of the verb to be.
I think.
Answer:
At the end of paragraph 1, when the author says “First, we must develop many different ways of putting the waste from these nuclear and chemical substances in, on, and around the earth” it helps shape the reader's perception of the text as by starting to go into more details and more ideas on poisoning the Earth.
<span>I think the answer is Mark Twain..</span>
<span>Sarah's hands were cold and clammy.
This sentence does not contain a pronoun. </span>
