In one fell swoop the bank wiped away the tentative benefits of this policy.

银行一下子就抹去了该政策带来的初步好处。

Whatever may have been the moment and the circumstances of its appearance in the scale of animal life, language could only have been born in one fell swoop.

不论是在动物的历史中何种时候何种环境，语言只可能是一刹那间诞生。

Productivity is not accomplished in one fell swoop.

工作效率不是一下子就能实现的。

It is impossible to finish this project in one fell swoop.

这项工程不是一下子就能完成的。

Want to know all in one fell swoop, means what also don't know.

想一下子全知道，就意味着什么也不知道。