There is a trace of her on the letter.

这封信上有她的印记。

There is a trace of chili in this dish.

这道菜里有微量的辣椒。

There is a trace of fatigue on his face.

他的脸上有疲倦的印记。

They found a trace of dirt on the floor.

他们在地板上发现了泥土的印记。

There is a trace of alcohol in his blood.

他的血液中有微量的酒精。

He showed a trace of unpleasure on his face.

他脸上露出了一丝不愉快的表情。

This medicine contains a trace of a certain chemical.

这药物中含有微量的某种化学物质。

Her tone was very grim, without a trace of warmth.

她的语气非常冷酷，没有一丝温情。

They detected a trace of metal in the ancient artifact.

他们在古代文物中检测到了微量的金属。

Scientists found a trace of pollutants in the water sample.

科学家在水样中发现了微量的污染物。