1.They......have been......(be)pen pals for a long time
2.Would you like(come)....to come......to my house next week
3.we used to...write....(write) to each other every mouth when we...were.....(be) at secondary school
4.Tomorrow, I(study).... will study....unit 2
5..we shouldn't(eat).....eat.......sweet food
6.We must(stay)..stay.......in bed when we have a flu
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