线索的英文：
trail
clues
thread (of a story)

参考例句：

The leakeys found a lower jaw, some skull bones, and some limb bones that provided the necessary clues
利基夫妇找到了可提供必要线索的一块下颌骨、一些头骨和肢骨。

She is not entirely clueless.
她并非毫无线索。

Hot on the trail.
即将找到失去的线索

The detective scoured the scene of the crime for clues.
那个侦探在犯罪现场仔细搜索线索

She searched about for clues to the mystery.
她对这个秘密查究线索。

I will give you some hints first.
我先给你一些线索。

He's all we got to go on.
他是我们探寻的唯一线索。

A vital clue to the killer's identity
有关杀人犯身分的重大线索

The police admitted that they were off the scent.
警方承认他们失去了线索。

The police are now on the scent of the culprit.
警方已获得罪犯的线索。

trail是什么意思：
v. 追踪；拖在后面；拖曳；落后于
n. 小径；足迹；踪迹；一缕，一股

There is a warm trail.
这是刚留下的新鲜痕迹。

The police trailed the thief.
警察跟踪小偷。

The children trailed behind their teacher.
孩子们跟在老师后面走。

clues是什么意思：
n. 线索；提示；情节
v. 为…提供线索

The police have no clue to his identity.
警察没有可以确定他的身份的任何线索。

The detective scoured the scene of the crime for clues.
那个侦探在犯罪现场仔细搜索线索

I have not a clue how to compose a waltz.
创作华尔兹曲我是一窍不通。

thread是什么意思：
n. 线，棉线，毛线；丝状体；螺纹；头绪，思路
v. 穿线于…，装胶片于…；通，通过；穿成

pipe bend with female thread
两头带阴螺纹的弯头

To hang by a hair thread
千钧一发

There is a common thread in these two stories.
这两个故事之间有个共同的线索。