One may use a polycrystalline sample rather than a single crystal for many studies. 我们可以用一种多晶样品代替单晶进行多方面的研究。
Poaceae is an important and big family among monocotyledon plants in China, and it has been researched in many aspects. 摘要禾本科是单子叶植物中的一个大科,国内对其已有较多方面的研究。