求翻译：一战爆发后，由于这一时期美国正处于工业化过程中，加之内战的影响，经济实力比较脆弱。因此，在这一时段内，自由贸易理论并未占据主导地位，推行的自由贸易政策表现为“阵发性”和“间歇式”。总之各利益集团若觉得自由贸易有助于他们从对外贸易中获利，便会支持自由贸易理论，并主张自由贸易政策；反之，又倾向于支持和要求实行贸易保护。无论是自由贸易政策还是保护贸易政策，都是对某一时期该国现实贸易活动的实践总结和反思，并随着实践状况发展而改变。是什么意思？

After the outbreak of the First World War, the United States because this period is in the process of industrialization, coupled with the impact of civil war, economic strength is relatively weak. Thus, in this period, free trade theory does not dominate the performance of the implementation of free

After the outbreak of the war, as a result of this period is in the United States in the process of industrialization, and the civil war, the economic strength of impact are more fragile. Therefore, in this period of time, the free trade theory does not hold the leading position in implementing the