Refining is the _______ of separating these impurities from the

Refining is the _______ of separating these impurities from the pure metal.
A、advance
B、process
C、access
D、result
【正确答案】：B
【题目解析】：advance发展；前进；增长；预付款；process过程；access通道；进入；机会；result结果
句意：精炼是从纯金属中分离这些杂质的过程。