I cannot forgive myself for not seeing my mother when she was sick in bed.
母亲病的时候我没能去看她,为这件事我永远不能原谅我自己。
After working with bees for many years, Professor Von Frisch was puzzled by something he had noticed again and again.
在和蜜蜂打了多年的交道后,冯·弗里施教授对他反复注意到的事感到迷惑。