比如当美国国会就气候变化问题展开辩论，其中一些立法者呼吁建立一个温室气体总量限制和排放交易系统时，那么另一些立法者就要问，为什么在中国声言拒绝的同时美国却要接受一个有约束力的承诺方案呢？
When Congress takes up the debate over climate change, for example, and some lawmakers call for a cap-and-trade system, others will demand to know why America should accept binding commitments to limit emissions while the Chinese refuse.