Ann is in hospital. — Oh, really I _____know. I ________her for a long time.

I regret you that Tom failed the exams. He regretted your advice. [ ]

下列交际用语使用得体的一项是 （     ）

simply couldn’t understand how it _____ that you did so much work within such a short time.

In such freezing weather,water pipes are easy to and water will escape from the. [ ]