1) A: Where’s Tess? B: . (she / leave) 2) A: . (I / buy / a new computer) B: Really? Can I see it? 3) A: . (Dave and Becky / move / to Brighton) B: I know. Ben told me last night. 4) A: . (I / tell / Kim / about the picnic) B: Good. Is she coming? 5) A: Would you like a biscuit? B: No, thanks. . (I / have / one) 6) A: . (we / come back / from our holiday) B: Did you have a good time?

1) A: Where’s Tess? B: She has left. (she / leave)
Explanation: B is informing A about the current whereabouts of Tess. The verb "leave" is in the past simple tense and "has" is used as an auxiliary verb to indicate that the action has been completed.

2) A: I have bought a new computer. B: Really? Can I see it?
Explanation: A is informing B about a recent purchase of a new computer. The verb "buy" is in the present perfect tense to indicate an action that happened in the past but has relevance to the present. B is expressing interest in seeing the new computer.

3) A: Dave and Becky have moved to Brighton. B: I know. Ben told me last night.
Explanation: A is informing B about the recent relocation of Dave and Becky to Brighton. The verb "move" is in the present perfect tense to indicate an action that happened in the past but has relevance to the present. B confirms that they are already aware of this information through Ben's communication.

4) A: I have told Kim about the picnic. B: Good. Is she coming?
Explanation: A is informing B that they have already informed Kim about the picnic. The verb "tell" is in the present perfect tense. B asks whether Kim will be attending the picnic, indicating curiosity about her response to the information.

5) A: Would you like a biscuit? B: No, thanks. I have already had one.
Explanation: A is offering B a biscuit. B declines the offer, stating that they have already had one. The verb "have" is in the present perfect tense to indicate an action that happened in the past but has relevance to the present.

6) A: We have come back from our holiday. B: Did you have a good time?
Explanation: A is informing B that they have returned from their holiday. The verb "come back" is in the present perfect tense. B asks if they had a good time, expressing curiosity about their experience during the holiday.