英语语法分析

Some residents voiced concern that the rice could threaten certain species of rare migratory birds.

一些居民担心这种大米会威胁到某些稀有候鸟的生存。

To test the idea, caged night-migrating birds were placed on the floor of a planetarium during their migratory period.

为了验证这个想法，这些在夜晚迁徙的候鸟被关进笼子里，并且在它们的迁徙期间被放置在一个天文馆的地面上。

He noticed that as they fluttered around in the cage, they often launched themselves in the direction of their normal migratory route.

他注意到，当它们在笼子里到处飞的时候，通常会朝着常规的迁徙路线的方向。