12. we for three hours before we decloed to take a break a)must be trekking b)had been trekking c) have been trekking 14 . a good way to .. a problem is to think about it calmly and carefully a)win b)beat c)gain 22.there was thick black coming out of the burning building a)fog b)smoke s)smog 24. mark said that he a great team in london the previous summer a)had had b)would have c) has had 28. what time does the train .. bristol? a)arrive b) get c)reach 29 .neither annabel .. sue has ever flown in a plane. a)or b) and c)nor