He fell off the bike ________.while he rodeB．while he ws ridingC．while he is ridingD．while on bikHe fell off the bike ________.while he rode B．while he ws riding C．while he is riding D．while on bike

A．Had we knownB．We had known itC．If we were knownD．If we know

ngD．weHrdly _______________ when we were told to stop.did we begin B．hd we begun C．were we beginning D．were we to beginA．did we beginB．had we begunC．were we beginningD．were we to begin