A:Fe2+、Al3+、ClO﹣、Cl﹣
B:K+、Cu2+、OH﹣、NO3﹣
C:NH4+、Na+、Br﹣、SO42﹣
D:Mg2+、H+、SiO32﹣、SO42﹣
— What is ______ favorite color?
— Purple. Look! My watch is purple.
75×37+75×63=____
There are so many people in the shop. You must _________ your things.