take the bear by the tooth 不是抓熊的牙齿

【例句】Walking along the back of a high and narrow wall is just to take the bear by the tooth. 【误解】仅仅为了卖弄就在高而窄的墙上行走，那无异于在抓熊的牙齿。 【正确】仅仅为了卖弄就在高而窄的墙上行走，那就是拿生命当儿戏了。 【说明】bear是一很凶悍的动物，用手抓它的牙齿无异于在用生命冒险。所以，take the bear by the tooth是表示“冒不必要的险”，跟put one's head into the lion's mouth（把脑袋放进狮子嘴里）的意思相同。