Use the be-passive form of the verb in brackets in the past simple. The report is the topic, and nobody knows who misplaced it: the report ___ during yesterday's move. (lose)

Բացատրություն

Was lost forms the requested past simple be-passive and keeps attention on the report while omitting the unknown agent. Got lost is a standard informal get-passive, but it does not follow the be-passive form required by the instruction.