The two speakers are having an argumentative essay about the case for Mars and whether or not it was important to spend money to send humans to Mars.
This refers to the arguments which are made by two or more people about a particular topic.
Usually, there is a claim made by one speaker which is backed up with supporting evidence and then the second speaker can make a rebuttal of the point of the first speaker and give reasons why the first claim is invalid.
We can see that this was used in the two articles; while the first speaker was talking about the need to go to Mars immediately and explore, despite the expense, the second speaker talked about the impracticablilty of the plan.
The second speaker rebutted the claims that humans needed to be there and get evidence of life by stating that robots can be modified to do that and the money can be better used to address problems on earth.
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https://brainly.com/question/11617771