Together, they weigh anywhere between 20 to 30 pounds, and they have to be crash proof.

它们加在一起重20至30磅, 而且找到它们就能够证明飞机发生事故的真正原因。

Ken Stonex helped GM Design a so-called crash proof highway test site called " The Proving Ground" .

Ken Stonex 帮助通用汽车设计了一个名为“试验场”的所谓防撞高速公路试验场。