The precise mechanism of this effect is not known.

There are several purported explanations for the precise mechanism which might result in death.

However, they are more frequently identified by their precise mechanism.

Granted, we do not know the precise mechanism of what takes place, but the results show its effectiveness.

Again, little is known about the precise mechanisms and molecules involved in this process of specialization.

The precise mechanism(s) that produce these benefits is not known.

The precise mechanism of this action has not been established.

Although the precise mechanism for this phenomenon is not known, a several factors are believed to be responsible.

What are the precise mechanisms involved in this process?

I challenge you to say by what precise mechanism the Commission might encourage relocations.