Previable
a. (胎儿)还不能生活的,可生活前的( 尤指尚不能生活于子宫外的)
🗣️ 情景例句
OK, Susan.
好的，Susan
He who makes no mistakes, makes nothing.
不犯错误，成不了事。
This is because they had no natural enemies until the arrival of humans and therefore did not need to develop flying wings.
这是因为人类到达这里之前，这些鸟没有天敌，因此，它们不需要发育飞行的翅膀。