注意：
P：美元价值下降使得日本和东欧购买美国的木头，而不是通过其他渠道
C：美国木头出口量增加
assumption：加强
B选项中提出美国木头的质量对日本和东欧是合适的，所以他们会购买，增强了原来的设定
D选项提到的需求不会急剧增加，感觉一开始理解成结果了，而不是用于加强的假设，

assumption 题目 选项否定就是削弱原文
原文结论 美国树木出口量将会增加
premise 美元贬值 日本生产纸的厂家会买美国的树木而不买别的resorces

错选a的原因是，产量增加的话自然原材料降价的情况下进口也会增加啊。。。谁来解释一下555

C是讲他们喜欢，但本身就有一定出口，美元便宜了就会出口增加，跟他们喜欢没有关系

结果：出口增加 原因：是美元贬值 外国购入需求增加

结论的假设 产品质量可以 因此便宜了 外国会购入 质量不行 外国不会购买

产量快速增加——对这个结论 米有影响

如果不管成本愿意使用美国产品——不管成本 那么这个原因就不成立 不是前提假设

B不完美，却是最佳答案

错选C，C是说他们不管成本，也就是说不管价格是否升降他们都不会增加购买量，削弱结论；而B是说他们的质量是好的满足日本生产商，所以他们会加大购买量

C. The reasoning does not have to assume that cost is the sole factor. However, it clearly assumes that cost is an important factor. Nevertheless,
it does not make any assumption regarding what the relative importance of cost and other factors might be. For this reason, it neither assumes nor
implies what might happen in the case that cost is not a significant factor.

C. Paper manufacturers in Japan and Western Europe would prefer to use wood pulp produced in the United States if cost were not a factor.

b我选对了，但是不明白c为什么错了，哪位大神可以帮忙解释一下！
是因为说成本不是因素，否定前提了吗

if U.S. wood pulp does not meet the minimum quality requirements of any paper manufacturers in Japan or Western Europe, then those manufacturers will purchase elsewhere. It follows that the reasoning depends on assuming that U.S. wood pulp does in fact meet those quality standards.
D.In fact, if such an increase were to occur, it would be even more likely that exports of
U.S. wood pulp would increase this year if U.S. wood pulp became internationally more competitive on price this year.