问题
单项选择题
硝酸士的宁中的马钱子碱（）.
A．配制成50mg/ml的溶液，测定旋光度，不得过-0.4°
B．配制成2.0mg/m的溶液，在310nm处测定，吸收度不得大于0.05
C．供试品溶液加稀盐酸5ml与三氯化铁试液2滴，不得显红色
D．供试品溶液加硝酸与水混合液，除黄色外不得显红色或淡红棕色
E．薄层色谱法
答案
参考答案：D
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硝酸士的宁中的马钱子碱（）.
A．配制成50mg/ml的溶液，测定旋光度，不得过-0.4°
B．配制成2.0mg/m的溶液，在310nm处测定，吸收度不得大于0.05
C．供试品溶液加稀盐酸5ml与三氯化铁试液2滴，不得显红色
D．供试品溶液加硝酸与水混合液，除黄色外不得显红色或淡红棕色
E．薄层色谱法
参考答案：D
| 补全对话。 | |
| Robin: What did you do last night? Harry: I listened to music all the time after finishing my homework. Robin: Do you like music a lot? Harry: Yes, of course. 1________. Robin: What's your favorite music? Harry: Rock music. Robin: 2________. Harry: I used to listen to pop, but now I prefer rock. 3________ I am tired of it. But rock is a kind of loud music. And the lyrics of rock songs are very meaningful. Robin: I think so. I listen to different kinds of music. Every kind of music has its own value (价值). 4________. Harry: Right. Do you play any instruments (乐器)? Robin: 5________. Harry: Cool! If I have a chance, I will surely enjoy it.
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