There are exercises that tauten facial muscles.

有些练习可以让面部肌肉紧绷起来。

When I grin, the stitches tauten.

当我咧嘴而笑，针脚便会绷紧。

I suddenly felt the fishing line tauten.

我突然感到鱼竿的绳子拉紧了。

Every nerve in his body seemed to tauten: he pulled out his wand, moved into the shadows beside the decapitated elf heads, and waited.

哈利全身的每根神经都紧张起来，他拔出魔杖，躲进那些小精灵脑袋旁边的阴影里等待着。