in duplicate

This contract is made in duplicate.

Send it in duplicate.

ruОтправьте его в двух экземплярах.

deSchicken Sie es in doppelter Ausführung!

The singular centrosome in animal cells duplicates during the S phase of interphase, in preparation for cell division later on.

Since the connection is often poor, my additions and comments appear in duplicate. Indeed, I insist on making sure they are gone.