碱性精炼
参考答案：
是加碱于熔融粗金属中，使氧化后的杂质与碱结合成盐而除去的火法精炼方法。
for his expert advice, John is often asked to help others with their personal affairs.
A．Having known
B．Being known
C．Known
D．Knowing
患者のプライバシーを他の人に漏らすなんて、医者としてある（）ことだ。
A.べからず
B.はずの
C.かぎりの
D.まじき
