The reaction conditions on oxidation of 2 - methylpyridine to 2 - acid by oxidation of potassium dichromate were studied.研究了以2-甲基吡啶为原料,以重铬酸钾为氧化剂,利用化学氧化法合成 2- 吡啶甲酸的反应条件....
One who cuts , polishes, or engraves gems.玉石匠开凿 、 磨光或雕刻''.'玉石'. ''的人....soap powders, detergents, and polishes.肥皂粉、洗涤剂和擦亮剂The bronze still hanging in the side wall, polishes.那铜牌仍旧挂在侧墙上, 被擦得铮...