You can see for yourselves the damaged condition and the reason why they are unassailable.
你们可以亲眼看到完好无损情况以及货物无法销售的原因。
Apparently what happened was that water collected on these tar pits, and the bigger animals like the elephants ventured out on to the apparently firm surface to drink, and were promptly bogged in the tar.
沥青坑里积存了水,大象那样的大动物冒险到似乎坚固的水面上去饮水,立即掉进了沥青坑。