It had only been there perhaps half an hour, starting from a single drop.

It is 20 years since I've had a single drop.

The journey of a single drop might take a full year.

Each had only a single drop of blood in it.

The fingers came away with a single drop of blood.

There was a single drop of blood on his lower lip.

Not a single drop of water had fallen for months.

All it takes is a single drop of the boss's name.

The king did not wipe away the single drop of his wife's blood.

At low tide there wouldn't be a single drop coming in.