涂装材料管理是生产时非常重要的环节。( )
参考答案：对
Bloomfield and Fries were known as the representatives of the ______ linguistics.
粗盐水浓度低的原因有（）
A.化盐桶内盐层低
B.盐水中含游离氯
C.化盐桶内泥渣多
D.淡盐水ph值过高
