氢的化合价为1，所以它通常只形成一个化学键。

Hydrogen has a ___valence of one, so it usually forms only one chemical bond.

这首歌曲的情感基调非常积极，让人感到快乐。

The song's emotional ___valence is highly positive, making people feel happy.

动词'吃'的配价是二，需要一个主语和一个宾语。

The verb 'eat' has a ___valence of two, requiring a subject and an object.