---- Where`s Mary now?Do you know?---- No but I he

问题补充：

---- Where`s Mary now?Do you know?---- No,but I heard

答案：

答案错了,应该选A,hear sb doing sth(在某个时间段)

======以下答案可供参考======

供参考答案1:

A供参考答案2:

she was

供参考答案3:

A. her singing