frontal furrow

例句：

1. 1. The patient's forehead was covered in a fine layer of sweat.
   病人的前额上覆盖着一层细密的汗珠。
2. 2. As she walked into the room, her frontal furrow deepened with every step.
   当她走进房间时，她的前额皱纹随着每一步加深。
3. 3.The old man's frontal furrow showed the signs of his age.
   这位老人的前额皱纹显露出他年迈的痕迹。