Some are open to everyone while others require certain conditions for being a member.

However to develop, the disease requires very wet conditions for an extended period of time.

It's ridiculous to suggest this is rare or requires perfect conditions.

The capture mechanism requires conditions that do not exist now.

In such cases, we do indeed seem to take decisions and choices as having required conditions.

But that would require certain conditions, and there's no sign of them coming anytime soon.

This would require tight conditions on the aid, they say.

That requires rules and conditions, which, on the other hand, we want to keep to a necessary minimum.

Mushrooms are not plants, and require different conditions for optimal growth.

The provision had been invoked only two or three times in recorded history, and its use required certain conditions.