油气初加工装置厂区外防火道应筑在（）m以外。
A.5
B.15
C.20
D.30
参考答案：C
B．不同晶体有不同的空间排列规律
C．晶体的空间排列规律决定这种晶体材料的用途
D．晶体的各向异性就是因为晶体有规则的空间排列规律
Half a month passed and the boy ________ all his money, so he had to turn to his friends for help.
A．ran out
B． ran out of
C．ran across
D．ran away with
