谢谢雅歌解释，一下就清楚了。原来以为只有加拿大进口美国，没想到美国也进口加拿大，数字也多，容易搞混。

来源: grasshaper 于 2015-08-17 09:57:39 [旧帖] [给我悄悄话] 本文已被阅读：次

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