迅即的英文：
at once; immediately

参考例句：

They were prompt to respond to our call for help.
他们对我们的求助迅即回应.

The company was(quick)off the mark in printing that book about the capture of the plane
公司迅即印刷那本有关缴获那架飞机的书。

Our agenda underwent a rapid change after the chairman's resignation.
主席辞职后,我们的议事项目迅即做出变动.

Their marital storms are infrequent and quickly lost
他们夫妻间的感情很少掀起狂风巨浪，有也迅即平息。

Our agenda underwent a rapid change after the chairman's resignation
主席辞职後,我们的议事项目迅即做出变动

once是什么意思：
adv. 一次，一回；一度；曾经
conj. 一旦；一…就…
n. 一次；一回

Once is no custom
一次不成例

Do it for this once.
就干这一次吧。

Gordon is at once modest and clever.(at once …and…既..又)
戈登既聪明又谦逊

This is the leap once of process of cognition.
这是认识过程的一次飞跃。

Slavery was once socially sanctioned.
奴隶制曾经为社会所认可。

immediately是什么意思：
adv. 立即；直接地
conj. 一…就

immediate bridge
立即齿桥

The law is effective immediately.
这项法律立即生效。

The evidence has no immediate bearing on the case.
该证据与本案无直接关系。

It was a complete breach with the immediate past.
它是历史上一次完全的突破。

We desire an immediate answer.
我们要求即刻的答复。