Mr. Smith is a most suitable candidate for such negotiator since his tact and quickness of mind are equal to the occasion.

这样的谈判史密斯先生是最合适的人选, 他机智敏捷, 随机应变。

It's a rather delicate situation and you'll need a lot of tact to handle it.

那是一个相当微妙的局面, 你需要用很巧妙的手段去处理。