The manager did not allow any of the staff to leave before five o'clock.
ALLOWED
None of the staff .................... five o'clock by the manager.
The two brothers look so alike that people often confuse them.
MISTAKE
The two brothers look so alike that people often .....................
We only discovered the leak after the ceiling had already collapsed.
NOT
.................... already collapsed did we discover the leak.
The government plans to introduce stricter regulations on air pollution next year.
DUE
Stricter regulations on air pollution .................... by the government next year.
I tried as hard as I could, but I was not able to convince her to change her mind.
MATTER
.................... tried, I was not able to convince her to change her mind.
She started working for the company twenty years ago and she is still there.
BEEN
She .................... company for twenty years.