29: We RODE, when suddenly, Jimmy HIT a stone.
30: While I SHOPPED someone STOLE my bike.
31: The pupils SAT quietly while the teacher WROTE some formulas on thr blackboard.
32: When the glass FELL on the floor, everyone STOPPED talking.
33: What DID YOU DO when the accident HAPPENED? (I think?)
34: It RAINED while I WAITED for the bus stop.
ofc, take my suggestions w/ a grain of salt! though I believe that's correct. past tense isn't too difficult :)