hosse 1.This is not my first visit to London …………………………………….. here before (I am-I am going to-I have been-was) 2.It is very crowded here.I wish…(there were a few people-there were not so many people-there is no one-there was so body here) 3.I have known him……………………………………………………………… I left school.(when-before-until-since) 4.Maria ‘s English is excelent.She speaks English ……………………………..…( very perfect-perfective-perfectively- perfectly) 5.Please let Tim……………………………………………………………………………….with you. (go –going- to go- goes) 6………………………………………..air is one of many problems we have to solve. (pure- polluted-dust –pleasant)