The correct answers are A and B. Ornithopods are typically bipedal herbivorous dinosaurs.

正确答案是 A 和 B。鸟脚类动物通常是双足食草恐龙。

However by the late Triassic many small bipedal dinosaurs were spreading out all over the planet.

然而，到了三叠纪晚期，许多小型双足恐龙遍布全球。

Before we get into bipedal and quadrupedal dinosaurs lets think again about a group of animals, mainly humans.

在我们进入双足和四足恐龙之前，让我们再想想一群动物，主要是人类。