We ____ (sat/was sitting/were sitting) when the doorbell _____ (rang/was ringing/were ringing).
were sitting/rang
He _____ (met/was meeting/were meeting) a lot of friendly people while he _____ (worked/was working/ were working) in California.
met/was working
When they _____ (left/was leaving/were leaving) the museum, the sun _____ (shone/was shining/were shining).
left/ was shining