题目内容：
The barriers to trade may take any form including import duties，import licenses，export licenses，import quotas，tariffs，subsidies and（ ）to trade．
参考答案：
答案解析：
单选题：The barriers to trade may take any form including import dut
- 题目分类：专业英语
- 题目类型：单选题
- 号外号外：注册会员即送体验阅读点！