Final answer:
Mark Twain's portrayal of the mate in 'Life on the Mississippi' using strong dialect suggests that the mate lacks manners and does not control his emotions, as seen through his commanding and abrupt way of speaking.
Step-by-step explanation:
Mark Twain's use of dialect in the excerpt from Life on the Mississippi serves to characterize the mate's manner of command. From the choices provided, the two that accurately describe the mate based on Twain's writing would be 'The mate lacks manners' and 'The mate does not control his emotions'. This is evident from the imperative and abrupt tone, alongside the use of exclamation marks, demonstrating the mate's lack of polite forms of request and his impulsive delivery of commands. The mate's manner of speaking stands in sharp contrast to the more courteous landsman way, therefore highlighting the mate's brusque behavior and emotional immediacy in his communication style.