They are not that old, so their record needs explaining.

On this point there was a lot more that needed explaining.

I need to try and explain some things to you.

But the manner in which he came to be on the ground needs explaining.

You won't have to explain things that don't need explaining.

You don't need to describe or explain what these tags mean.

But there was another matter, more immediate, that needed explaining.

"I don't need to apologize or explain myself to you."

The advantages of free trade in a global economy ought not to need explaining to anyone.

Its value, given the power of spy satellites, needs explaining.