71.      
　　 In this argument the author predicts a nationwide labor¹ shortage in the near future.The basis for this prediction is an increasing demand for highly skilled workers, especially in technical and professional fields, coupled with a slow-growing labor force and a government proposal to cut funds for aid to education. At first glance, the author's argument appears to be somewhat convincing: but further reflection reveals that it is based on some dubious² assumptions.

      In the first place the author assumes that the present labor force is immobile and that the demand "for highly skilled workers will have to be met by workers who are entering the labor market for the first time. Recent American history, however, shows that this assumption is entirely³ unfounded. At the beginning of the Industrial Revolution most Americans were farm workers, but by the end of that revolution most had become factory workers. Thus, even though the labor pool remained relatively⁴ constant during this period, the number of farm workers decreased and the number of factory workers increased. This example clearly demonstrates the mobility⁵ of the labor force.

      In the second place, the author assumes that the government proposal to cut funds for aid to education will have a significant negative impact on the ability to train workers in technical and professional fields. The fact is, however, that the percentage of students who rely on government aid for their education is relatively small, so the effect of such cuts would be negligible.

       In conclusion, this argument is unconvincing. To strengthen the argument the author would have to show that the present work force was relatively static and that the proposed ours i educational aid would have a deleterious effect on the numbers of high skilled workers available to enter the work force in the future.
72.       
　　The author of this government agency memorandum⁶ argues that the government should not spend any money this year fixing the bridge that crosses the Styx River, given the limited resources available for building and repair of roads and bridges. The author reasons that this bridge is less important than others because it is located near a city with a weakening economy, and because the city's small population is unlikely to contribute enough tax revenue to Justify⁷ fixing their bridge. This argument is unconvincing for four reasons.

      First of all, the author unfairly assumes that the importance of a bridge is determined⁸ solely⁹ by the economic condition of nearby cities. This assumption overlooks other criteria¹⁰ for determining a bridge's importance—such as the number of commuters using the bridge, the role of the bridge in local emergencies and disasters, and the impact that bridge closure would have on the economies of nearby cities. Without accounting¹¹ for these other potential factors, the author fails to provide a convincing argument that the Styx River Bridge is unimportant.

      Secondly¹², the author fails to provide any evidence that other bridges are more important than the Styx River Bridge. Without such evidence, we cannot accept the author's conclusion that no government funds should be directed toward maintaining the Styx River Bridge.

      Thirdly, the fact that the nearby city has a weakening economy does not prove that the city will not contribute significantly to tax revenues. Perhaps tax revenues are based on property taxes, which are not related directly to economic conditions. If so, and if property values and taxes are high in this nearby city, then the city would contribute significantly to tax revenues, and the bridge would be important to maintain those property values and the revenues they generate.

      Finally, the author assumes that a city should receive government services commensurate with the tax dollars it contributes. Substantiating¹³ this assumption requires examining the proper duty of government. However, the author provides no such examination. Accordingly, this assumption is simply an unproven claim.

      In conclusion, this editorial fails to substantiate¹⁴ its claim that the Styx River Bridge is not important enough for the government to spend tax dollars to maintain and repair it. To strengthen the argument, the author must account for other factors that also determine a bridge's importance, and must compare the importance of this bridge relative to other bridges.