关节断裂

brass knuckles───指节铜环

stacking trucks───堆垛车

backing tracks───日文歌曲

cracking on───v.继续疾驶；满帆前进；继续干下去

cracking up───vt.撞坏；衰退；赞扬；突然大笑起来；精神崩溃；吹捧

cranking handle───曲柄摇手

packing cases───装运货物的箱子

Just stop cracking your knuckles.───就是按手上的关节。

aim of this experiment was to see if his mother was right and that cracking the knuckles causes arthritis4.───这个实验的目的就是看看他母亲是否正确，因为他母亲认为扳指关节会导致关节炎。

medicine prize went to a physician who, for fifty years, cracked the knuckles on only his left hand to test his mother's contention that knuckle-cracking causes arthritis.───医学奖授给了一位内科医生，他50年来每天不断扳左手手指，以验证自己母亲说扳手指会引发关节炎的话是否正确，他的结论是：妈妈，你错了。

Some claim that cracking knuckles leads to arthritis, but the studies claim that it only causes minor damage to soft joint tissue.───据说指关节响动会导致关节炎，但研究表明这只对关节软组织有轻微的损伤。