____ was it _____they discovered the entrance to the underground palace?— Totally by chance.

It was reported that more than five hundred Chinese people ___________ in Lu Dian earthquake on Aug, 3rd, 2014.

We hadsat down at the table, when the phone rang

He was_____weak_____ he couldn’t stand up

The doctor will see you again next week. _____, you must rest as much as possible.