I hardly know where I am when I hear about a thing like this and am completely knocked down and out.
我听到这种事后简直不知道自己身在何处,感到天昏地暗了。
英语百科
Knock-down kit
(重定向自Completely knocked down)
A knock-down kit is a kit containing the parts needed to assemble a product. The parts are typically manufactured in one country or region, then exported to another country or region for final assembly. Variant names include knockdown kit, knocked-down kit, or simply knockdown, and the abbreviated KD or CKD.