立方晶系的晶格常数特征为()A. a ne b ne c,a= beta = gamma =90^ circ B. a=b=c,a= beta =y=90^ circ C. a=b ne c,a= beta = gamma =90^ circ D. a ne b ne c,a ne beta ne y ne 90^ circ

A. $$ a \ne b \ne c,a= \beta = \gamma =90^ \circ $$

B. $$ a=b=c,a= \beta =y=90^ \circ $$

C. $$ a=b \ne c,a= \beta = \gamma =90^ \circ $$

D. $$ a \ne b \ne c,a \ne \beta \ne y \ne 90^ \circ $$