1) Last week, some students of our class had a cold. They kept coughing and sneezing
2) You must wash vegetables carefully or the dirt from the farm on them will make you sick
3) Have you ever seen the dolphins before? No, i have not
4) Mr Tan isn't sittung in his office. He left two hours ago.
5) She is going to fly to Moscow next week with her uncle
6) He didn't go to the party last night  because he was sick
7) Tuan is being taken to the zoo by his father today