Let's fix it at seven o'clock. 我们定在七点钟。

A:Hello,Tom!Do you have any plans for this evening?
你好，汤姆。你今晚有安排吗？
B:Nothing special.
没什么特别的安排。
A:How about having dinner with me?
和我一起吃晚饭如何？
B:That's great!I would love to.When?
好极了，我非常愿意。什么时候？
A:Let's fix it at seven o'clock.Ok?
我们定在7点钟，怎么样？
B:No problem.However,maybe I should come early to help you prepare the dinner.
没问题。不过，或许我应该早点来帮你准备晚餐。
A:Don't worry.I will arrange everything.
不用担心，我会安排好一切的。
B:All right.See you tonight.
那好吧，今晚见。