例句：
Laughter is one of the most infectious expressions of emotion.
笑是最具感染力的情感表達方式之一。
The civil servant's expression, however, did not change, not so much as by a flicker.
然而，那位公務員的`表情還是那樣，絲毫沒變。
I don't sing perfectly in tune, but I think I put more expression into my lyrics than a lotof other singers do.
我唱歌不是特別合拍，但我認爲我唱得比其他很多歌手都更富感情。
She spoke in a quiet voice but used remarkably coarse expressions.
她說話聲音很小，但是用了些特別粗俗的字眼兒。
This forms the basis for our mathematical expression for the electric field.
這是電場數學表達式的基礎。
