帮LZ贴一下题目. 这题我也不懂, 哪位NN给解释一下? 13. Defense Department analysts worry that the ability of the United States to wage a prolonged war would be seriously endangered if the machine-tool manufacturing base shrinks further. Before the Defense Department publicly connected this security issue with the import quota issue, however, the machine-tool industry raised the national security issue in its petition for import quotas.
Which of the following, if true, contributes most to an explanation of the machine-tool industry’s raising the issue above regarding national security? A. When the aircraft industries retooled, they provided a large amount of work for too builders. B. The Defense Department is only marginally concerned with the effects of foreign competition on the machine-tool industry. C. The machine-tool industry encountered difficulty in obtaining governmental protection against imports on grounds other than defense. D. A few weapons important for defense consist of parts that do not require extensive machining. E. Several federal government programs have been designed which will enable domestic machine-tool manufacturing firms to compete successfully with foreign toolmakers.
13. Since the size of the machine-tool manufacturing base presumably has implications in area beyond national security, one might find it surprising that the industry raised the security issue in its petition. C, the best answer, explains that the industry turned to this issue because others tended to be ineffective in efforts to obtain governmental protection.
A explains why the industry might NOT raise the security issue, since it suggests that it might have raised the issue of jobs instead. B explains why the industry might NOT raise the security issue about import quotas, since it suggests that the Defense Department had no interest in import quotas whatsoever. Neither of D and E is relevant to the industry’s choice of strategy for securing import quotas. | 
