Discuss how well reasoned you find this argument.

　　1.The following is a memorandum¹ from the director of personnel to the president of Get-Away Airlines.

　　"Since our mechanics are responsible for inspecting and maintaining our aircraft, Get-Away Airlines should pay to send them to the Quality-Care Seminar, a two-week seminar on proper maintenance procedures. I recommend this seminar because it is likely to be a wise investment, given that the automobile² racing³ industry recently reported that the performance of its maintenance crews improved markedly after their crews had attended the seminar. These maintenance crews perform many of the same functions as do our mechanics, including refueling and repairing engines. The money we spend on sending our staff to the seminar will inevitably⁴ lead to improved maintenance and thus to greater customer satisfaction along with greater profits for our airline."
 
　　2.The following is a letter to the editor of an environmental magazine.

　　"The decline in the numbers of amphibians⁵ worldwide clearly indicates the global pollution of water and air. Two studies of amphibians in Yosemite National Park in California confirm my conclusion. In 1915 there were seven species of amphibians in the park, and there were abundant numbers of each species. However, in 1992 there were only four species of amphibians observed in the park, and the numbers of each species were drastically reduced. The decline in Yosemite has been blamed on the introduction of trout⁷ into the park's waters, which began in 1920 (trout are known to eat amphibian⁶ eggs). But the introduction of trout cannot be the real reason for the Yosemite decline because it does not explain the worldwide decline."

　　3.The following is a letter to the editor of the Atticus City newspaper.

　　"Former Mayor Durant owes an apology to the city of Atticus. Both the damage to the River Bridge, which connects Atticus to Hartley, and the traffic problems we have long experienced on the bridge were actually caused 20 years ago by Durant. After all, he is the one who approved the construction of the bridge. If he had approved a wider and better-designed bridge, on which approximately the same amount of public money would have been spent, none of the damage or problems would have occurred. Instead, the River Bridge has deteriorated⁸ far more rapidly over the past 20 years than has the much longer Derby Bridge up the river. Even though the winters have been severe in the past several years, this is no excuse for the negligence⁹ and wastefulness¹⁰ of Durant."
 
　　4.The following is a letter to the head of the tourism bureau on the island of Tria.

　　"Erosion of beach sand along the shores of Tria Island is a serious threat to our island and our tourist industry. In order to stop the erosion, we should charge people for using the beaches. Although this solution may annoy a few tourists in the short term, it will reduce the number of people using the beaches and will raise money for replenishing the sand. Replenishing the sand, as was done to protect buildings on the nearby island of Batia, will help protect buildings along our shores, thereby¹¹ reducing these buildings' risk of additional damage from severe storms. And since the areas along the shore will be more attractive as a result, the beaches will be preserved and the area's tourist industry will improve over the long term."