No admittance except on business.

Electricity made candles of little use in our life.

There is nothing useless in nature.

Please don't take any trouble on my account.

John claimed that the dishonest salesman had tricked him into buying a useless piece of machinery.

John claimed that the dishonest salesman had tricked him into buying a useless piece of machinery.

When we rush to complete our work, we make needless errors.

Not a word to anyone, please.

Keep it quiet.

Don't worry!