0 (a) is incorrect, as you need a subject for 'clean', because the phone wasn't doing that action.02br 00(b) 'as' is better with this verb form; I would use 'was cleaning' with 'while', but that is a personal preference. 0-
0I try to do some corrections:02br 02br 00(a) While / When / As John was cleaning / clean the fan, the phone rang. (which verb is better?cleaning or clean? ) 02br 02br 00(b) When / While / As he cleaned the fan, the phone rang.0-