trace
单词辨析：
指某人、某物曾经出现或存在过的迹象。
The police found some traces of the robbers.
警方已经找到强盗的一些踪迹。
The killer disappeared without a trace.
杀手消失得无影无踪。
There was no trace of any drugs in his blood.
他的血液中未有毒品存在的任何迹象。
指帮助弄清事情缘由或帮助破案、解开谜团的线索。
At last she found a clue to the puzzle.
最后她找到了解开那个谜的头绪。
Are there any clues we can use to find the murderer?
有我们能用来找到凶手的线索吗？
We have no clue as to where she went after she left home.
我们对她离家后去往何处毫无线索。
指某事属实、即将发生或存在着的迹象。
Dark clouds are the sign of heavy rain.
乌云是大雨将至的预兆。
At the first sign of danger, the submarine will submerge.
一有危险迹象，潜艇就会潜入水中。
There was no sign of a roadblock.
那儿没有设置路障的迹象。
相关例句：
She learned to draw by tracing pictures out of old storybooks.
她通过描摹旧故事书上的图画学会了画画。
The newspaper contacted his grandmother to trace his present address, and later doorstepped him at his home.
报纸联系了他祖母，查到了他现在的住址后便前往登门采访。
Staff will be able to trace calls at the touch of a button.
工作人员一摁按钮便可以追踪电话。
The aircraft vanished without trace
飞机消失得无影无踪。
Throughout, he showed no trace of self-pity.
他从始至终都没有表现出一丝的自怜。
Only people who can trace their family history in Kuwait back before 1920 are entitled to citizenship.
只有其在科威特的家族史可以追溯到1920年以前的人才能获国籍。