用蒸馏水稀释0.1mol/L的CH3COOH时,始终保持增大趋势的是 [ ]
A.c(CH3COOH)
B.c(H+)
C.c(OH-)
D.c(CH3COO-)
答案:C
普通味精的主要成份是______,使用时温度一般不宜超过______.
The operation of the storage, processing and assembilng of the bonded goods and consignment sales should be approved by and registered ______ the Customs.
A.for B.byC.from D.with