2 A: Why is the jeweller's around the corner closed? B: Because it (rob) last night.

Explanation: The event happened 'last night', indicating the past simple passive. The structure is 'was/were + past participle'. The past participle of 'rob' is 'robbed'. Since 'it' refers to 'the jeweller's' (singular), we use 'was'.

Answer: Because it was robbed last night.