lculations, had they been done by hand,______all practical value by the time they were finished.

been trying to advise them not to act that way, but my advice had no_________on them.

On the day before the party, Mr. Smith told his men to __________ no effort to make sure the guests enjoy themselves.[ ]

So difficult ____ it to work out the problem that I decided to ask Tom for advice.[ ]

He left the room______the door locked last night.