invalid

无效的

【例】When the quorum is less than two thirds, the decisions adopted by the board meeting are invalid.

当法定人数少于2/3时，董事会通过的决议为无效。

invalidate

使无效

【例】Any dispute arising out of any particular shipment shall not invalidate the remainder of the Contract.

任何一批货运所引起的争执，均不得使本合同的剩余部分失效。

invaluable

价值不可估量的，非常宝贵的

【例】The manager gave us a lot of invaluable advice on writing business letters.

在写商业信件方面，经理给我们提出了许多非常宝贵的意见。