–Have you finished your experiment report, Jane?--Oh, my god! I’ve _______ forgotten all about that.

The lecture is so attractive that the audience are listening_________.

To understand the grammar of the sentence, you must break it       into parts. 

The conference was _______ fixed for the 10th, August, but later the unexpected landslide(泥石流) in Zhouqu in Gansu province, made us put it off.

 As he works in a remote area, he visits his parents only ____.