Some looked like little eels, most have paired teeth at the headend.
有的看上去像小鳝鱼，大多数的头部有着成对的牙齿。
2
For instance you might have a website or service that says it "confirms" that a transaction happened, but there was no actual state change at the headend.
例如，可能会有一个网站或者服务说它“确定”某个事务发生了，但实际上在首段没有状态改变。
3
His head struck the bottom when he dived into the 6 ft end of the pool.