unless and until

基本解释

Dubbed Pay-What-You-Can, the training is a free gift, unless and until you decide to pay for it.
除非你愿意付钱，在你付款之前，培训都是免费的礼物，这被称作“付你能付”。
Unless and until this is done other policies, no matter how apparently appealing or effective in normal times, will be futile at best.
如果做不到这一点，其它政策最多也只能算是徒劳无功——无论它们在平时看起来多么吸引人或有效。
U.S. and Israeli officials say they will have nothing to do with Hamas unless and until the group renounces violence and agrees to recognize Israel.
美国和以色列的官员说，除非哈马斯放弃暴力并且同意承认以色列，否则他们不会同哈马斯组织打交道。

"For sure the military will not only clear and secure the area, but ensure unless and until the area is taken over completely by the civil administration, and the writ of the government is restored and peace and normalcy return to the area, the military will remain in the area,".

We won't know unless and until somebody talks about what the actual secret is.
NPR: Invoking the State Secrets Privilege
Unless and until the Krasnoyarsk radar is destroyed, for example, all deals should be off.
CENTERFORSECURITYPOLICY: At What Price Arms Control Agreements?
Sprint does not intend to comment further unless and until an agreement is reached.
FORBES: Softbank Must See The Value in Clearwire's 2.5 Ghz Spectrum