The three components of a scientific argument are:
1- THE CLAIM
The claim is a conclusion achieved that answers the original question.
2- THE EVIDENCE
The evidence is used to support the claim. It has to be sufficient, correct qualitative, quantitative and appropiate.
3- THE REASONING
The reasoning is the part that links the claim with the evidence, showing why the data correctly supports the claim made at the begining of the process.
The diction of Steinbeck here in apparently describing the dustbowl conditions of the Dirty Thirties is speaking of "tenant men" or presumably men who were tenant farmers perhaps who were allowed to live on the land in return for working it and that they "scuffed" their way home indicates that the dust was so thick they had to scuff but also perhaps that since they could barely make a living under the poor agricultural conditions they did not walk confidently but scuffed.
Topic sentence
Robots can already clean floors and windows.
Concluding sentence
We can use computer software to communicate with robots and give them commands.