Communication is also reliable because messages are guaranteed to be delivered once and only once when using JMS.

通信还是可靠的，因为使用JMS时系统保证消息被传送一次而且仅传送一次。

youdao

A receive or pick activity must be executed once and only once if a process is to be executed normally.

如果流程要按照正常方式执行，则接收或选择活动必须执行一次，且仅执行一次。

youdao

Reliable messaging refers to the ability of a sender to deliver a message once and only once to its intended receiver.

可靠的消息传递是指发送方向它所期望的接受方传递一次并且只传递一次消息的能力。

youdao

And once he said: "Four-fifths of our troubles in this life would disappear if we would only sit down and keep still."

VOA: special.2010.12.23

Milton will only use the word career once in his poetic oeuvre and it comes -- it will come pretty soon, actually, in Sonnet Number Seven.

弥尔顿在他的全部诗歌作品中只用过一次事业这个词,我们马上就会看到，在十四行诗的第七行。

耶鲁公开课 - 弥尔顿课程节选

It's a comedy that you only get once you performed and once you know what's happening, and

这种喜剧只有你自己明白，只有你自己知道发生了什么，

街头表演很有趣 - SpeakingMax英语口语达人

Once this is done, and only once it is done, does it make sense to think about action items such as making work more interesting, providing more job security, or rewarding performance with bonus plans?

FORBES: An Idiot's Guide to Employee Engagement

During the entire hour-plus-long keynote, the word "Vista" was only uttered once, and then only in the context of Windows Live compatibility, and in the same quick breath as Windows XP and Windows 7.

FORBES: Magazine Article

One particular example has it guiding users though an efficient power nap, by starting a timer once they've started dozing and only waking them once they've come out of a deeper sleep state.

ENGADGET: Sony patent application puts electrodes in a pillow, eases you out of slumber