without rhyme or reason

• adj. 莫名其妙(无缘无故)

例句

用作形容词 (adj.)

1. She got angry without rhyme or reason.
   她莫名其妙地生起气来。
2. They surrendered the lucrative bonds for no reason.
   他们莫名其妙地放弃了那些正在升值的公债。