一个英语长句,谁能帮帮我分析一下逗号后面的结构,
The economic links between China and Australia have become so strong that the Aussie dollar is now used by many foreign exchange dealers as a proxy for the yuan,a guide to where the Chinese currency would be trading were Beijing to remove its restrictions.
逗号前面都没问题,后半句看不明白,特别是那个were的主语是什么?