prick one's own thigh with a needle to keep himself awake; study diligently; work hard at one's lessons
Related Translations:
引: Ⅰ动词1.(牵引; 拉) draw; stretch 短语和例子引弓 draw a bow2.(引导) lead; guide 短语和例子引路 lead the way; 他把我引进会客室。he ushered me into the reception room. 一条沟把溪水引到田间。a ditch diverted water from the stream into