请选择与划线部分对应的翻译：The world used to be simpler. It was divided into the "have" nations, and the many more "have not" nations. Put it in another way, there was the "First World" and the "Third World". In recent decades, many Asian countries have joined the "haves". Certainly, by most standards, places like Japan and Singapore are rich. But just as it seems that they might relax, they are suddenly faced with a new challenge: the economic rules have changed.
A.但是正当他们觉得可以放松一下的时侯，他们突然要面临一个新的挑战：经济规则改变了。 B.但是他们刚刚要放松的时候，他们就面临新的挑战了：经济原则变了。 C.就在他们刚要放松的时候，他们就面临新的挑战，经济规则已经改变了。 D.但是他们可能已经变轻松了，他们却突然面临新的挑战，经济原则改变了。正确答案A
