Нужно - put present perfect or past simple. a: hi sarah! i (not/see) you for a long time. (you/be)? b: i (go) to china to teach english a: wow! how (be) it? b: very nice! i (stay) in beijing and ) eight-years-old children. a: how (you/find) teaching them? b: great! the children (be) clever and (learn) very quickly. what (you/be) up to? a: nothing as interesting as that! i (just/finish) my exams b: that's good. do you have any plans for the summer? a: yes, i (buy) a ticket to italy. i'm planning to stay with my cousin, sabrina, for a month. b: that's great! sabrina is a lot of fun. i'm sure you'll have a great time. don't forget to send me a postcard.