Each one has a left half that binds the long strand in one place, and a right half that binds it in a different place, and brings the long strand together like this.
每一个都有一小段可以和长链在某一个地方结全起来 而另一小段可以结合在长链的另一个地方 这样就可以把整个长链改变成这样的结构