Being honest is usually thought of as a virtue and undoubtedly this is the ________.

A．issue

B．case

C．event

D．factor

根据晶体物质的晶格结点上占据的质点种类（分子、原子、离子）不同与质点排列方式不同，把晶体分为几种类型（）。

A.1种

B.2种

C.3种

D.4种