Synthetic antigcns
[医] 综合抗原
🧩 词语组成解析
🗣️ 情景例句
Sir, I thought this was an emergency.
先生，我想这是一位急病患者。
I played ping-pong this morning.
我今早在打乒乓球。
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。