Правильно ли я обозначила времена предложений в страдательном залоге?
It is well known that one form of energy can be changed into another. – Present Indefenite
Thus, the mechanical energy of falling water is turned into electric energy. – Present Indefenite
When an object loses its potential energy, that energy is turned into kinetic energy. – Present Indefenite
We have already seen that energy of some kind must be employed to generate the electric current. - Present Perfect
These needs will continue to grow as more motors and melted metals are used in industry and more electric current is employed in everyday life. - Future Indefenite

не совсем правильно(((1ок2ок3ок4главное предложение в perfect,a вот must be employed тоже present indefinite passive.5гл.предложение -future ind.,а are used тоже present indefinite passive.is imployed тоже pr.ind.