1. I (not see)……haven't seen……… him since last Christmas.
2. We (go)………have gone…….. to Vung Tau several times.
3. He has already (write)………written………. to his parents.
4. Lien (not prepare)……hasn't prepared……… her lessons yet.
5. They have just (receive)……received ……..a package from their grandfather.
6. Miss Huong (teach)……has taught…….us English for 2 years.
7……has….she (feed)…fed…her dog yet?
8. We have never (take)…taken…… a bus to school before.
9. Next week, my uncle (come)…will come……..back home for Christmas.
10. My teacher is explaining the lesson but I (not understand)……don't understand…..what he is saying.
11. Lan (be)……was…….my next door neighbor when I lived in Hai Phong.