Given the task definition and input, reply with output. In this task, you are to Translate German text to English

Beim Betrieb mehrerer Einspritzungen (1; 2; 3) wird einem der Einspritzregelventile, z.

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
When operating multiple injections (1, 2, 3) one of the injection control valves, z.