You'll enter through one, you'll exit through three, but after this action, inside you will be. What are you going to do?

You do not want me to be permanent. But to avoid me is a mistake. You can let me help you. But precious time it will take.

Silky and soft we are, perfuming your lives. Take us to your love, but beware of our knives. What are we?

There are 30 people cruising on a boat in the Thames. However, when they emerge from sailing beneath London Bridge, not a single person is on the boat. How?

You can find me in the darkness, But never in the light. I make laughter lethal, And agreement into sight. You can find me in the soil, But never underground. A bunch of snakes together, Their voices do astound.

I sell invisible things. After I sell what I have, I still have it. I sell what everyone needs but often don't want. Who am I?

One falls but never breaks; the other breaks but never falls. They are opposites. They cannot coexist, but neither would know where they end or begin without the other.