In vertebrates, the immune system provides a multiple defense against internal parasites.
在脊椎动物中，免疫系统提供了对体内寄生虫的多重防御。
2
The fossil remains of the first flying vertebrates, the pterosaurs, have intrigued paleontologists for more than two centuries.
翼龙是第一批会飞的脊椎动物，它的化石遗迹已经吸引了古生物学家两个多世纪。
3
Huxley reasoned that flying vertebrates must have been warm-blooded because flying implies a high rate of metabolism, which in turn implies a high internal temperature.