shoot a marble while keeping one's knuckles on the ground
knuckle的用法和样例:
例句
用作名词 (n.)
Our fingers bend at the knuckle. 我们的手指在指关节处弯曲。
Guidry had the 1 of the best sliders ever and should teach him, and Moose should teach him the Knuckle curve. 古得利已经有了史上最厉害的滑球,必须要好好传授他,然后轮到穆西纳,也必须要教他指关节区球。