The hardness of mica is （ ）.
举一反三
- For soft tooth surface gear transmission, the hardness of the tooth surface should be selected A: Pinion tooth surface hardnesslarge gear tooth surface hardness B: Pinion tooth surface hardness≤large gear tooth surface hardness
- 武当派的武功以刚为主，刚柔并济。（ ）The martial art of Wudang School emphasizes hardness, and couples hardness with flexibility. （ ）
- Hardenability和hardness是同一概念。
- There are three common hardness testing methods used in practice, that is, ____, ____ and ____.
- Water is characterized by . A: hardness B: flaring up C: downward flowing D: changing