Number of bars/measures per line

Hi. I'm new to Musescore and am trying to learn as I go.
How do I space 12 bars (measures) evenly into 3 lines? (The first 2 bars have the opening of a melody, which my pupils need to complete. So - 10 bars are emty, but need to be spaced out, to give them space to complete the melody).

I can do it on Finale, but am trying to switch to musescore.

Thank you!

:-) Birgit ♫