(一):I Sincerely hope that our cooperation a pleasant and successful one.

我真诚希望我们的合作愉快、成功。

A: I Sincerely hope that our cooperation a pleasant and successful one.
甲: 我真诚希望我们的合作愉快、成功。
B:Yes, that's also my wishes.
乙: 是的，我也希望如此。
I wish you a good day and hope that our cooperation a pleasant one!
祝您有美好的一天，也希望我们合作愉快！
Let's hope for good cooperation between us.
希望我们合作愉快。
Wish a good cooperation!
希望我们的合作愉快！

(二):Let's raise our glasses in a toast to our pleasant cooperation!

让我们举杯，为合作愉快干杯！

A： Let's raise our glasses in a toast to our pleasant cooperation!
甲: 让我们举杯，为合作愉快干杯！
B: Cheers!
乙: 干杯！
Here's to my life long partner!
为我的终身合作伙伴干一杯!
Let's drink a toast to our friend Ms. Brown!
为我们的朋友布朗女士举杯！