vacant line
常见例句
- A plausible reason is that all the dinosaurs had been killed off, except the line that evolved into birds, and the placental mammals speciated into the ecological niches that had been left vacant.
一个可能的原因是所有恐龙除进化为鸟的一支外都死掉了，胎盘类哺乳动物才在被空闲出来的生态龛中得以进化。 返回 vacant line