Feder
n. 菲德尔（姓氏）
🗣️ 情景例句
Always full of surprises.
总是出人意表。
He who fears being conquered is sure of defeat.
怕吃败仗的就要打败仗。
It is the natural frequency of emission of the hydrogen atoms in space and was discovered by us in 1951;
这个频率是空间氢原子释放的自然频率，是在1951年被人类发现的。