题干
It was not until the subprime loan crisis(次贷危机) ____ great damage to the American financial system that Americans ____ the severity of the situation.
A：caused, realized
B：had caused, realized
C：caused, had realized
D：was causing, had realized高考资源网
答案(点此获取答案解析）
B
上有一点
，它到
的距离与它到焦点的距离之和最小，则点