Incrustant
水垢
🗣️ 情景例句
Can I tell him that?
我可以把这消息告诉他吗？
He insisted that we all be in his office at one o'clock.
他要求大家一点钟到他的办公室。[大学英语四级]
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。