crack [cut, make] a joke about ...
…について冗談を言う[とばす]
crack a whip
むちを鳴らす
crack an egg
卵をコツンと割る
crack one's knuckles
指の関節をポキポキ鳴らす
crack one's knuckles
指の関節をポキポキ鳴らす
crack out laughing
わっと笑い出す
crack under the pressures of one's job
仕事の重圧で体をこわす
cracks in solid rock
硬い岩盤の亀裂
cracks in the walls [the mirror]
壁[鏡]のひび(◆中に食いこんでいるのでin)