到那时，我已经失去了对话的线索。

By that point I'd lost the ___thread of the conversation.

在我看来，杰克和拉尔夫之间的对立形成了叙事真正的线索。

The antagonism between Jack and Ralph, who can be regarded as the novel's main characters, forms - in my view - the real ___thread of the narrative.

在整个小说中，一丝微妙的讽刺线索连接着各个情节。

Throughout the novel, a subtle ___thread of irony connects the various episodes.