jīn shǔ / tōng cháng / yóu / xǔ duō / xiǎo jīng tǐ / zǔ chéng / yīn cǐ / bèi / chēng wéi / duō jīng tǐ金属通常由许多小晶体组成,因此被称为多晶体。Metals are usually composed of many small crystals, which is why they are called polycrystals.