It was____the old worker came that we____the experiment.
The __________ of the Itaipu Dam took 30,000 people seven years.
__________ is possible that everyone will become happy if they change the habit of unhappiness.
It's said that the hotel to be completed can __________ more than 1,000 guests.
My mother asked me to __________ the dirty dishes from the table after dinner.
The palace __________ the 16th century will be torn down.