Giúp mk vs 8.he has studied English for 4 year -It is... 9.how long have ago did you know her? -how long.. 11.when did she began work in this company? -how long. .. 12.this is the first time I have seen such a tall man. -this is... 13.this is the first time I have eaten such a good meal -I have not... 14.the last time she got an A in English is last month -she has not... 15.have you ever seen an elephant before? -Is this. .. 16.It is 3 year since I last taught in BHH school -I haven't. ... 17.the last time she traveled by bus was 6 year ago -It is.... 18.I haven't met fatter man than this man -this is the. ... 19 .she began conducting the survey 3 days ago -she has.... 20.he has written that novel for 6 months -he started. ..