The transformation required something which only the human holder of the ring could provide.

The effort of will that such transformation required was beyond her present capacity.

Actually, such a transformation requires great cunning and is seldom done.

These transformations are normally slow and require several days, but at times they took place under the eyes of the observer.

This transformation requires a large amount of heat, which will stay in the battery for a long time.

Such an enormous transformation required foreign partners and foreign capital.

What this transformation will require of companies and top managements is much harder to decipher.

Knowing whether a transformation requires oxidation/reduction or not is actually useful.

However, Fran says that transformations require a great amount of willpower.

The transformation of hydrogen requires a great deal of energy.