is been 是什么时态

　　She's been told that her husband is being harshly treated in prison.

　　她被告知她丈夫正在监狱里遭受严酷的对待。

　　There have been riots before and the situation is volatile.

　　先前一直就有暴乱，局势变化无常。

　　We have been given reassurances that the water is safe to drink.

　　我们得到保证说这水适合饮用。