NO.PZ2016010801000101
问题如下：
The trading agreement of customs union does not contain:
选项：
A. the removal of all barriers to import and export among members.
B. the removal of all barriers to labor movement among members.
C. the adoption of common trade restrictions with non-members.
解释：
B is correct. The removal of all barriers to labor movement among members is the characteristic of common market.
考点：Trading Blocs, Common Markets and Economic Unions
解析：消除成员之间的一切劳工流动障碍是共同市场的特点。所以B选项正确。
这五个不同程度的贸易同盟，有没有什么好记的办法？