All the runners would begin with their toes on the scratched line.

所有赛跑者开跑时都要把脚尖放在起跑线上。

Judging by the scratches on your hands, I'm guessing a new cat.

从你手上的抓痕来看，我猜是一只新猫。

Based on the scratch marks they found on the teeth, it turned out that the primary diet of Diplodocus wasn't the leaves of trees; it was ground cover, like ferns and horsetails.

根据他们在牙齿上发现的划痕，原来梁龙的主要食物不是树叶；这是地被植物， 如蕨类植物和马尾草。