学习笔记：
★fingernail：手指甲
例句：I have the fingernail clippers. 我有指甲钳。
★knuckle：指节
例句：Our fingers bend at the knuckle. 我们的手指在指关节处弯曲。
★thumb：拇指
例句：The little child took her ear between her thumb and forefinger and tugged it playfully. 小孩用大拇指和食指捏住她的耳朵，拉着玩。
★finger：手指
例句：A mantis nipped my finger. 螳螂挟住我的手指。
★palm：手掌
例句：Buddhist monk sat with folded palms. 和尚合掌打坐。
