Variable behavior
[医] 可变性活动
🧩 词语组成解析
🗣️ 情景例句
He should just about get by in the exam.
他这次考试还能勉强及格。
The tongue is not steel yet it cuts.
舌头不是钢，伤人似刀剑。
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。